PZ nails it.
Here’s what I think is going on. He’s dug himself into a deep hole with his record of saying stupid things, and he doesn’t see a way out, because ultimately he still thinks he was totally right about everything, and trying to defend himself would involve making more stupid statements. There aren’t any misunderstandings, we all understand perfectly well what he was saying, we just think he’s wrong. And he’s sort of aware that trying to change our mind about that would require reaffirming many of his previous stances, yet he’s a smart guy who knows the wind is blowing in a new direction, so he’s just going to get more dissent.
He’s dug this hole, so now he’s going to just sit in it and tell everyone they’re poopyheads who don’t understand him. That’s fine. Go right ahead. I think rms has found the right position for himself at last.
Source: rms resigns