Why would it bewildering? The guy created a great thing, but is now one of the main impediments in the way of its success. I'd rather have his principles outlive him. His creation is more important than he is.
That being said, I 100% agree with you! I don't care if everyone considered RMS to be a saint. Free software is about freedom and software, not a cult of personality.
Look at who many people here work for. Look at the power that Big Tech holds. Look at my dead comments and realise that there's a crucial battle boiling beneath the surface, one that they definitely don't want you to know about. The war on general-purpose computing is continuing and they are going after those taking the side of freedom.
Why? Because he does a bad job in his role of movement leader and made himself irrelevant.
He's irrelevant even in niche circles -- how often do places like HN speak of anything related to RMS other than the drama of him being removed and later re-added to the FSF? Compare with the coverage of other prominent figures. For them we typically have regular non-drama news of what they're actually doing. For RMS we mostly have discussions of "is he a dinosaur?" and once in a while, "Stallman was right about something he said 10 years ago".
They use morality to strike against powerful men and in turn feel a snippet of power themselves.
No need to contribute to free software to the same degree as him to prove him wrong, that's too much trouble. Their contribution shall be retribution. A destructive action, instead of a more commited creative one.
"but there is genius in their hatred
there is enough genius in their hatred to kill you
to kill anybody
not wanting solitude
not understanding solitude
they will attempt to destroy anything that differs from their own
not being able to create art
they will not understand art
they will consider their failure as creators
only as a failure of the world
not being able to love fully
they will believe your love incomplete
and then they will hate you
and their hatred will be perfect
like a shining diamond
like a knife
like a mountain
like a tiger
like hemlock
their finest art"- Charles Bukowski