I'm not sure that that's what rms did.
This Guardian article makes me think that he has been unfairly treated. Even though I think that he is completely wrong to assume that an elderly man could reasonably expect that a very young person is having sex with them for any reason other than either direct coercion (violence, mental-abuse/gaslighting) or the indirect violence of capitalism (need to support self or family [1]).
https://www.theguardian.com/education/2019/sep/17/mit-scient...
I think it is quite clear that he was explicitly NOT claiming that the accusor was willing, but that she was coerced into appearing willing. I think it is quite clear that he also calls for more care and clarity in the language around this and the post on Medium gets it completely wrong, as does your last phrase.
1. This can include drug dependency, can also include the need to pay for "luxuries" like going to college: it's pretty much all the same to me -- these things are withheld due to force in our society. The picture is even clearer in the extreme case of "voluntary" sex work by people in developing countries.
There are a lot of similarly coerced situations in our capitalist societies. You want to eat? Go down the mine.