Some do. My brother, for example, has several dozen political or gun-related blogs that he reads religiously. He doesn't even keep a bookmark list--he just remembers all of them, and visits them one by one when it's time for reading, keeping track of which posts are new. I showed him Google Reader and suggested it would streamline things greatly, but he just grunted it off and said he liked doing things the way he liked doing things.
There are not a lot of "content websites" that I follow (Fefes Blog, Beautiful Pixels, MacRumors...) but rather content aggregation websites like HackerNews or Reddit, which I use to get my daily dose of news (not just tech but all kinds of categories). And yes, I check those manually, often on my phone in the respective apps, and it does not at all feel like a hassle. I've tried using Google Reader and other feed managers like Feedly but never got used to them.
For personalized news I look at the two social sites I follow (App.net and Twitter).
And the best part about Reader (and now The Old Reader, for me)? The comments come from people I mostly know or are vouched for by people I do, so there's a distinct lack of inane Reddit-y comments.
If you wonder what the practical problems are, consider a person that has the (possibly job-related) constraint that they cannot look at their twitter client whenever they want. If that person now wants to stay informed about something without missing an update, they are essentially screwed with twitter and other information-stream based services. At this point I am very certain that what I just described is not an outlier but rather the reality for a large section of the general population.
I don't need everyone to find RSS as useful as I do and I'm fine with the fact that others have different usage patterns and preferences. But I wish everyone saying "meh, what's the big deal" would realize that others find RSS to be the best fit for them and are well-justified in worrying about its decline.
HN and Facebook are enough for me.
Do your favorite researchers post comments at Facebook regarding their latest papers?