You're losing lots of quality content by removing those TLDs. I'm using 3 of the listed ones just because they're cheaper and found similar ones to be a good indicator of "this is less likely to be blogspam, and more likely a personal space".
Ya, I use them for personal space. My last name is five letters ending in "st" and I managed to snag that three-letter st domain which I was pretty happy about :) I know a lot of people seem to hate them--and a lot of non-tech-types don't always seem to understand that they are domains--but I think they're fun, and I love finding peoples' personal homepages (mine is currently borked, of course, but not because of the st domain).
There is also a lot of junk on those TLDs, especially the inexpensive ones, outweighing the ratio of good-to-crap found on the big few.
Blocking them in search lists doesn't stop you finding them indirectly by them being mentioned in content elsewhere, or from even more direct referrals, so the non-junk ones can be found those ways. I tend to find useful content on .com et al as much those ways as by direct search these days anyway.
