The Wrong in Less Wrong (LW) is referring to the objective ("mind-independent" or intersubjectively verifiable) failure, error, inconsistency, illogical argumentation, irrational behavior. You are wrong if you take the wrong, or simply less effective, path to reach your goal. LW is trying to improve your map so that you'll be able to find a better and more effective path. If you were perfectly aware of what you want, then with regard to your epistemic state, there would be the right thing to do. But LW does not claim to be right but merely less wrong. More importantly, LW does not tell you what you ought to want but rather how to figure out what you might actually want and how to obtain it. Therefore to ask how a group that claims to be less wrong can be doing X, which is wrong, implies that they not only claimed to be right, rather than just less wrong, but also that you know about their objectives and that X is the wrong way to reach them. It would be less wrong to argue that doing X is wrong given certain objectives but not that doing X is intrinsically wrong, that X is wrong in and of itself. After all people might simply want to do X or want to reach Z, X being the path leading up to Z.

I might call wedrifid morally bankrupt for eating meat simply because he likes bacon. But since I expect him to be aware of the consequences of eating meat I do not call him wrong. I'm only proclaiming that subjectively, from my point of view, he does have a poor taste. On the other hand, if I believed that he actually not only wanted to minimize suffering but that he also does assign more utility to reducing the death of beings than culinary considerations, I'd call him wrong for eating bacon just because it tastes good. I would call him wrong on the basis of failing to account for his true objectives in what he is actually doing. Yet I would not declare the activity of eating meat to be wrong itself but in the context of certain circumstances as a means to an end regarding his volition.