Maybe I sound old fashioned, but isn't a vasectomy if you're unmarried kind of like taking the bullets out of a gun? Sure, it's safe, but is there really any point to the gun anymore?
Don't get me wrong; for a husband and wife who didn't want children anymore, it would be ideal. But for a single guy, it just seems like the wrong time. He doesn't know if he's going to want children if/when he gets married. He may not want them at the moment, but meeting someone genuine could give him a new outlook. I know that they're reversible, but it's still the idea of paying for the procedure and doing that to your body.
I don't know... I'm kind of against cutting into the body and sewing it up again unless it's absolutely needed.