Nah not surprised that people are absolute maniacs. Imagine being that sad and bothered about someone you've never met on the internet disagreeing with you.
The thing is that society has legitimised these nutters.
For example, if a woman gets a letter for a smear saying 'women aged 16-64 need to book an appointment' (my other half just has), I could - easily - complain about the use of the word 'women' used in that context, start a social media campaign and get thousands of people complaining about inherent NHS transphobia. Because you don't need to have a uterus to be a woman of course - that's the narrative now. It should be 'all persons with a uterus aged 16-64' naturally.
Formerly, doing something like this would be the work of a lunatic, but now this is happening all the time.