There actually *were* some people over at 4chan who expressed irritation that Claire was trans*. While this forum community is vaguely-small most of the time I think, the comic does get a lot of readers. In addition though there's always someone griping over there about something, whether it's comic artists getting injured (Jeph's hand injury, Rich Burlew's hand injury, etc.) or something else.
Who knows though. I've never been able to figure out why Danielle Corsetto's comic gets hit as often as it does.
et al
4chan is just concentrated internet, cutting out most of the places Young Adult Males don't frequent. It can be compassionate or coarse, rude or polite, accepting or phobic. A certain term that used to mean a bundle of sticks is used casually, and it is the birthplace of bronies and, I just learned, now has a /lgbt/ board. Trying to pin it down is a fools errand.
It is, to my knowledge, no longer frequented by those who like to use DDOS and related tools. They likely have nothing to do with this. But hey, the only boards I ever looked at with frequency were /wg/ and /trv/.
As for the thread on /co/, it appears that beside the vulgarity, they favor the same pairing/s most commented upon here.