Well, Matto, who mostly posts in the Politics forum, is a very Catholic Catholic (not to say catholic) with little if anything of the Baptist about him. But Baptists is, for the most part, what we are. The owner of the site is a Baptist Historian based in Montana and Atlanta, Bruce Gourley.
If you mean "Why Baptists" in the sense of "Why are you Baptists?", most of us have reasons we can give based on theology, ecclesiology, etc., but for most of us I think the real reason is it's what we were brought up to be, and like Solomon said, when we are old we by and large still aren't departing from it. Even though, for some of us, "it" has undergone sea changes right under our feet.