Lol dude. Plenty of people who speak English as a second language can speak (and write!) fluently and “naturally” with few errors.

This is confirmation bias. You assume anyone who writes a certain way online is a native speaker, but you have no way of actually knowing that unless they explicitly say so.

Damn, I just assumed they were screening to ensure real users acting in good faith. Didn’t expect them to actually be rejecting people.