I've noticed that more people aren't using signatures anymore. (Myself included for the moment.) I think it's just 'cause some of us have gotten over the initial excitement of things after becoming more experienced, and now we're more focused on things other than bragging about what equipment we have and whatnot. At least that's one reason I can think of.
that doesnt go for me, i havent got anything to brag about. i just like having my gear in my signature for others to see if they are interested.