If he started the season hot, and the Mets were in contention, and then he did this in August and September, he'd be a choker, and someone who can't handle the pressure of NY. It doesn't really matter when he slumps, he'll get ripped for it regardless.
The Mets are not bad because of Ike. He's part of the problem, but not THE problem. There is not one aspect of this team (outfield, infield, SP, RP) that is league average. They're just a bad team.