I’m going to post in this thread against my better judgment, but only to respond to DH.
You assume that most people who sit in kollel and learn for about an hour a day would not do that hour if they weren’t in kollel. Have you taken a survey? I haven’t, but I know that it isn’t true for me. I can’t learn for a twelve hour yeshiva day. (At least not on a regular basis. Every once in a while during intersessions I do it.) But I am koveah itim without any social pressure, and I am far from the only one, after all I do have chavrusas ;-).
Another factor, though mostly irrelevant, is that once someone is in a situation where his “me” time is the time he takes to learn as opposed to the time he takes from learning, he may learn more.