Do companies complain a lot about used game sales? I recall seeing one or two statements about it, but nothing excessive. Then again, this is about the only site I go to for news, so I don't know much about what the other companies say and do.
I've been one to complain about DLC, but I try not to every time I hear about it. It's here to stay it seems, and I've already voiced my concerns.
One thing I think it is with these topics, new people who join message boards such as this might not have talked about these topics before. As an example, before joining NWR, I've never before discussed things like sales figures and casual vs. hardcore, so they were new and interesting topics to me whereas everyone else was sick of them. That's one reason, I think, they keep getting brought back up.