Why? Well because I want to up their rep of course. Alot of the older members like plmnko (Sorry hun, no offense meant, you're just the closest example with a high post-count and account age at hand, though I don't even know if you're a good example TBH) have massive rep scores as a result of the old rep-war, among other things. Now it's nice when they +rep a new user, because the lucky guy goes up a few bars, but when they hit them with a - boom! poor fucker's in the red. With little to no recourse other than creating a new account (Because damn, you can bend over backward for the people in the hentai games section and you're still not getting +rep. Hell, alot of content providers don't even have full green bars!). And that's just with normal use of the rep system, when you've got someone actively abusing it like what happened with the MnF sub, it's like watching... I dunno, a really unfair fight started by some prick.
I've bitched up-hill and back down about this elsewhere, and it's obvious nobody's going to change the rep system. So I figured, fuck it, I'll just +rep spam people that haven't been here for a long time, to give them a better chance the next time a certain someone decides to throw a -rep tantrum.