You know in an in-group of friends you could call yourself that depending on context and it would be a joke but in a professional setting I would classify this as sexist. In fact, if you look at the link someone else posted in this thread, you see that women are very uncomfortable with his behaviour, even going so far as developing Stallman avoidance tactics.

To be clear, I generally agree with his stance on software freedom and don’t want to diminish his great intellectual contributions to software but I think he is not a good person to be put in a position of power.

Ok, then leave that part out.

Not OP, but maybe something like this.

Lemmy.ml is the flagship instance of the Lemmy software, hosted by its developers. The community on this instance is dedicated to leftist ideals and particularly interested in privacy and FOSS.

Highly unprofessional behaviour is based?

Sounds like it might be good for relatively static content but what about highly dynamic content?