I mean, the question answers itself. First of all, she's a 4, so stop wasting your time.
Second, it's always bad news when a girl has all guy friends. I had an ex-GF who had this close guy "friend" who she would talk to on the phone for hours, see him a lot, and generally hung out with him as though there was nothing wrong with it.
I don't care how much of a DJ, independent guy you are, but if you're in a serious relationship with a girl, you just don't expect her to be doing all this stuff with other guys who are supposedly their "best friends". I see things from the other side now since I've been the other guy (never a "best friend" though, because I avoid that), but as much as you don't think the girl will ever get with the guy, the reasoning is that IF the 0.001% chance that she does suddenly find him attractive, you want to negate that chance. Strange, but that's the thought process.
Anyways, before I go too far, basically, I had my share of arguments with her about this guy, and she never dropped him, so I bailed. Luckily we weren't that compatible anyways, so it wasn't difficult. I think I was just attracted to the fact that she wanted to rip my clothes off every time she saw me. I was in high school then, so raging hormones took over. Not the deepest relationship I've had, that's for sure, but it's funny how despite this, the same thoughts about her not having this guy friend around still rang true.