Constructing a situation in which Marvin Minsky somehow was blameless for his relationship with a known pedophile and child sex trafficker and situations directly resulting from that relationship, then projecting the reactions of other people through that situation, is not merely a
mistake with words. Coupled with his at-best-real-gross chinstroking about minors, consent, and statutory rape in the past, it demonstrates a pattern. And it's a pattern that, obviously, made enough people uncomfortable as to want to not associate with him--as is their right.
MIT doesn't have to give Richard Stallman a do-nothing job. The FSF doesn't have to give Richard Stallman a (nearly) do-nothing job. Everybody makes mistakes, sure. You make up for those mistakes by doing good and doing right and if Stallman wants redemption, literally nobody is stopping him from going after it. They're just not bankrolling it. There's a difference here.