Eh, it's an acquired taste I guess, though that could be said of pretty much anything. There is a lot of conventions on what faces mean, inside jokes, etc. - once you get used to those, I'd still say it's better than most webcomics, though calling them "good" may be a bit of a stretch.
I don't deny that lesswrong rage comics would probably be pretty bad, and may repel people more than it attracts - and those it would attract may not be the ones we want. It's just the best example I can find of a collaboratively made webcomic that's worth reading.
People have been asking this question here a lot lately (not sure, why, but still). MoR has been by far the most effective ad for LW so far, but this is a one-man effort. I wonder if a web comic drawn by the regulars based on, say, recent posts and comments would be another way to get people interested. Just to set the bar really, really low, here is my quick impression of this post (the idea is stolen from #lesswrong, but the obvious bad pun is mine):