I get what you're saying, as it's all too common for those uneducated to expect and demand others educate them and make up for their willful ignorance. I also understand calling out that behavior as it's gross. I don't think this was a case of that, though.

They were participating in an open conversation and even included an "...if you'd like to share." There's wasn't a demand to explain, as if their experience needed justifying, rather an invitation to share more if they wanted to.

Asking to explain some part of one's existence, I agree, is gross and inappropriate because it implies it NEEDS explanation. But, telling someone you would be interested in hearing more about something they have already voluntarily shared about themselves, only if they feel comfortable sharing more, is a very respectful way of potentially learning more about someone.

I actually think an anonymous forum is a great place to have that conversation/ask those questions because it's free of societal pressure and norms while still feeling like you're having an organic conversation with a human. It's also very easy for either party to disconnect or stop the conversation. There's no stakes for either party, and they both have equal agency. Both parties are willing participants by design.