I disagree.
I believe he sincerely believes he can serve effectively, and even do some good. Sure, if I were in his place, I'd run as fast as I could from that nest of thieves and let them stew in their own wastes, but perhaps a true patriot might believe he can at least minimize the damage, and perhaps even offer a push in a more positive direction.
Whether he can do this, or even if its possible, is a question only time and history can decide. But I would keep a close eye on his tenure in the West Wing. If he winds up resigning, or is pushed out, it can only mean the worst.