Bill Simmons is ok when he is doing his whole "voice of the common fan" thing. He is absolutely awful when he tries to sound like an expert. He badly misunderstands statistics, often admits to not watching the games, etc.
And what is worse, since he has decided to be a sort of self proclaimed NBA expert, he has been needlessly dumping on the celtics to try to establish some sort of "objective" cred.
There is a reason why he lost to his wife in the whole pick'em thing two seasons in a row.