He's right that young people have agency and can make informed decisions about themselves, but fails to recognize the social pressures that means that young people often aren't in a position to say no, or even understand that they can can say no. There are financial, social, and even legal power imbalances between minors and non-minors that make it impossible to assert that certain interactions are consentual, even if they aren't of a sexual nature. It's these power imbalances that are the issue, not whether or not a young person has enough factually to understand what they are consenting to. Interactions like this are abuses of the power that adults have over children, and that's a big part of what makes them so disturbing.
I'm getting my one lick in because I know litigating this will be futile, people will defend RMS to the bitter end regardless of what he says or does, and I'll probably just be flagged for my trouble.
RMS blogged many times over many years about his beliefs that child pornography and pedophilia should be legal and socially acceptable. He also has a history of creepy behavior around women. He clearly is not asexual.
If RMS wasn't a part of Epstein's shit, it's only because he wasn't sociable enough to fit in with that crowd, not because he wouldn't be into it.