Many of the people I do have online conversations with speak English as their first language. I kinda get by but you native speakers really underestimate how hard it is to express oneself in a foreign language. Concepts work differently, metaphors don't really translate, references you have used for decades don't make sense.
Like in German I am actually somewhat eloquent and texts I write don't look like a person with a head injury wrote them.
(Sparked by some of the comments to my recent article about Cory Doctorow telling me how my writing sucks and is unreadable because of grammar mistakes and typos.)
@tante Having an opinion and a voice in the discourse shouldn't be gated by one's eloquence or grammar. If those people were pointing out errors in order to improve your argument, then it was noble, albeit insensitive. If they were doing it to dismiss your argument, then they were being defensive (ok, unwrap why and what they're really saying) or gatekeeping (ignore).
@tante Also, FWIW, I tend to read slowly and spot lots of errors in published texts from English-first writers. I haven't noticed any in yours, which makes me think those people went out of their way to look for errors. If true, that would be acting in bad faith, IMO.