It's rarely as simple as "I can't live with being a virgin anymore!!1"
I imagine that in a lot of cases, loneliness, low self-esteem, a general lack of interest or enthusiasm about anything, and a sense of helplessness are also heavily involved. It's one thing to have a "dry spell," but it's another thing entirely to be fully convinced that you'll be alone and miserable for the rest of your life.
This is true, that shit fucks with you as the years pass by. I'm sure a lot people saying "being in a relationship isn't all that great" or "it isn't that important" have a girlfriend/boyfriend right now or have had one in the past. I'm sure for you people being in a relationship is second nature, a normal, everyday thing. But when you've been successful in pretty everything else in life but for some reason you keep failing when it comes to dating and relationships you can't help but feel like shit.