It is an opinion, and thus we discuss it, is that a bad thing? It is a good thing to discuss things like when someone makes a tier list of what he finds best to start with because we throw in our experiences to create something meaningful. To not discuss and just let it stand there is to silently agree and say "yes everyone should do like this" while discussing means we disagree and want to argue for why some units are better as well as hear more from him why he feels some units are placed where they are.

That said, i guess he made the tier list from how he sees units in accordance to how easy they are to get. So Bernice as an example got into a lower tier because you might not even get her.

Anyhow, promoting discussions is what a forum exists for. It would actually be weird if he did not get different opinions about his choices.