I have no problems with tier lists/discussion topics. Personally, I find them helpful for devising strategies and deciding which character will get me through a certain tough spot. I appreciate the effort put in by the debators because it really opens up information that is new to me and offers me a clear look at things.
That being said, I haven't seen problems branching from tier discussion so I really find it hard to believe tier discussion has a negative effect on the game/community.