Do you like portals?
Yes, those huge sites with a load of information on almost every topic. News, politics, stocks market, sports, cars, travel, weather, family, dating, shopping, career, cuisine, horoscopes etc.
Something of that kind:

I've always felt overwhelmed by those. The current of information is so strong it almost carries you away. Who knows where? You came looking for some specific information but spent a lot of your precious time giving your attention to just about anything you got curious about momentarily. Maybe that was the intent?
Portals are quite widespread on the web. What I like about them is that they communicate an immediate sense of belonging to a society. You are made familiar with the latest news, trends, developments and social concerns in a matter of minutes. Some portals allow visitor comments for their articles so that you can get involved and start to feel part of the community. Sounds great, right?
It can well be. But it somehow does not attract me enough to be a regular visitor of those portals. I only land there occasionally following a specific link or when searching for something in particular and being directed there by Google.
To tell the truth, I try to avoid portals.
Why? There are a few things that annoy me and make my experience drop drastically.
Overwhelmed by a wall of content
Portals welcome you with a pile of content which is far more than a single individual can handle. You're going to have to dig through it trying to find what can be useful to you. You'll have of course to understand first the category division and the interface concept of this particular place. And I'll tell you that is not easy since designers of the portals have obviously made it their goal to gather all forms of content delivery in one single place. Text, imagery, videos, elements of forums and social networks, voting etc. Seeing upfront I will have to give it here some substantial effort makes me feel weary already. I just wish I could close the page and go elsewhere. If I can, I do just that and feel relaxed.
Distractions from your path
Many people only come looking for something in particular. They could be interested in the latest weather updates. But that's not easy to stay focused on the task when there are distractions all over the place. Above there is an excerpt from the latest news, on the right there are horoscopes for the current month, in the middle you see most popular articles from people's shopping lists. No, of course you don't have to look at them, but honestly, can you ignore them all? You look at one thing then at the other and now you dropped your search and reading something completely unrelated to weather. That's what you were originally interested in, remember?
Luring you to keep you long
The generous offering of a vast variety of information is bound to distract you and have you wasted your time. You look at one seemingly interesting article about job interviews then jump to a recommendation of places to visit, now there is an interview with some known sportsman and here it goes. You spent an hour over random content you only got interested in for a moment. Of course, the site observes what you're browsing through and feeds you more relevant content to lure you away from your business. Even the complex navigation structure helps. By the time you find the information you were looking for, you've inevitably have wasted time on a few things that have drawn your attention. Do you still remember what you came for originally anyway? And did you notice how long ago you actually came?
Destroying your flow
This one I strongly dislike over all other reasons. The abundance of content of all kinds not only distracts you but leads inevitably to you seeing things that are simply incompatible with your current state of mind. Imagine you've got interested in career advices available on the site. You've been reading through them, you've tuned yourself to the flow, this article says about bright prospects on your career path and now the last update brings to your attention the latest news about Siemens to lay off over 4000 people. How's that for your prospects and believing in yourself? Or you've been reading an article about relationships, family and children and now the site brings to your attention the state statistics about divorces. Do you still in a sweet mood or do you ask yourself now: "How long could our family last anyway?" Right… You were in a sunny singing mood when you came and now you left depressed not believing in your future. I wonder if designers and concept analysts of those portals are even aware of this issue.
Intentionally unusable search
On a huge variety of places I could observe the search function not functioning at all. Copy the title of some article on this site, paste it into the search box and hit "Go". It never finds it. But it does have a lot of suggestions about what could probably "help" you with your search. Of course. Let me tell you what would help me with my search. It would help me if your search could just search. Nothing more. And nothing less. Try to look for some gibberish which does not exist guaranteed. No, it won't find it. But it will give you a lot of suggestions for content that is "very similar" to what you were looking for. You mean, the articles suggested also consist of random characters? No? Then how can they be "very similar"? No, don't tell me, I already know the answer. The search was never designed to work, only to feed your more and more content to keep you stayed. Thanks, I'm leaving right now.
Low quality of content
Another concern which I see confirmed on a regular basis is that the quality of content offered by an "all-in-at-once" place is usually low. It's not that the information is wrong, but it is often below par, compared on a scale focused site and communities set. If you think about it, where would a portal team find resources to deliver first-class content for all of the dozens of topics they've been supporting? Sure it's possible to aggregate some from other places but only if they permit it. The ones which create high quality content tend to keep it to themselves and not distribute it to everyone. And hiring professionals to address each topic separately may well be out of the capabilities of people behind those portals. So, unless you're really bored or don’t care about what you're getting you may well go to those portals. I'd prefer a dedicated place which may only cover one theme but do it with quality and professionalism often missing from those portals.
Unstable, unfocused and unprofessional community
The same quality concerns apply very much to the community of those portals. Some keep forums or allow visitors to comment on articles, so it gathers some sort of a portal community. Due to the unfocused nature of the place, the community also gets assembled of occasional people from the street. Some of them do know well one or the other matter, but it's a mere chance if you ask something and get a qualified advice. The chance is usually very low to non-existent. One reason is that professionals do not keep to unprofessional communities. There can actually be no community at all. Portals are visited by a great number of random people. Sometimes they have something to say to a random topic or comment a random article, after which they leave and even forget their membership credentials for good. That is of course no foundation for any sort of stable and professional community.
Would you like to know my idea of the best web portal ever? It looks like this:

Focus on offering quality content and make sure it's accessible. If it's good and relevant, I will find it. Short of that, nothing will attract me to your place.
And no, I'm not interested in your vision of a web portal as a place to spend my time. My time is too valuable to waste it in this manner.