I can use your same arguments against you in the same way you used them against me, but its a pointless endeavor. Maybe address the substance/point being made instead of the character or motives of the poster since you don't know those.

As far as "do posts like this help a player or coach get better" - I happen to think its a silly question to even ask on a fanboard. I don't think they do anything to help/hurt but to flip it back on you, does effusive praise and ignoring shortcomings help someone improve? It's the other side of the same coin.