You have some interesting insights and analysis on your blog (aside from the statistical study inspiring your questions about 20- and 30-somethings being single or paired-up). Looking forward to reading more there ...
As for me, I've been single most of my dating life. Since coming out at 21 (it was different in the early '90s than now), it seems most guys I've known were either looking for a temporary relationship (a "lay-over") or were more career oriented, therefore, making lesser time to develop a relationship.
But since most gay guys I've known were so concentrated in major cities (whereas I prefer to live in a suburb, getting more space for my mortgage buck), most city-centric guys, whether in their 20s or 30s, feel dating someone outside the city limits just isn't worth the car ride out of town, especially where nearby gym hours and club venues are a greater concern for them. It is disappointing, but this is the sad reality.
As a result, my evaluation about being in a committed relationship has gradually changed. I've been perceiving dating and eventually being with someone as NOT as some sort of sign of love and companionship, but more of a psychological state of co-dependency and neediness. As a result, I know I've become much more distant, if not icy, toward more recent guys who have attempted to know me. Mistrust, belief of insincerity, and their "true" intentions dominate my perceptions of the individual, regardless who he is.
But these are my perspectives. To some, it may sound like I'm cynical or have given up. But when you see yourself not having a good track record of ever having had a boyfriend (despite the few guys who have stepped into and exited my life quickly), then you come to realize it may never occur, especially since I'll be 40 in two years.
Thanks for bringing up your interesting observation and question.