Actually I know exactly what the guy was talking about. My experiences of TAs are that they are lazy, lousy slobs who just get into the teaching job for the money (which is a pittance). They argue about the hours they work and they will say that they cannot help you because it's gone half an hour off their appointed time. I can say flat out that you're quite averse to criticisms. The guy wasn't even mentioning anything particularly bad. It was one sentence. Chill out. You're fortunate to have known good TAs. What's so offensive about sharing shitty experiences of our past TAs?
I think you got my point. I wish I could have gone to this magical college where every Prof and TA actually cares about what/who they are teaching, but it turns out UW-Madison is like most colleges, it just doesnt happen that way.