my guess it is partly because some regulars have extreme views and are not really open for a positive discussion or accept other views and then many topics venture off into immature name calling and is not a welcoming atmosphere!
We all know that "we" often take exception to a team for what a supporter says. I do not want anyone having ill feelings toward the team I support because of some statement I said that was not intended to be offensive but perceived that way. I do know several coaches that do not post for that very reason. let's just say that posting is contrary to their better judgment!