Unfortunately there are people whose purpose in life is criticizing and humiliating others. Be it free writing, or free software, a blog or any volunteer activity. They feel that it's free and it must have a higher .quality than bigtech/big-authors.
There are many people who aren't native English speakers, I'm among them; but if years ago they were completely excluded from participating, now machines help non-native to better interact with the world around them! But machines make evident mistakes so, if you know the language you can correct it by hand before posting (like I always do) while if you don't know, you just let it go.
I am for complete inclusion in this world so if someone wants to share their sexual stories despite little English knowledge, we have no right to exclude them, but let's rather HELP them.
I remember once a guy who wanted to write text by hand, not knowing English so well; in a rimming shene he wrote "language" instead of "tongue" because the word in neo-latin languages is the same -Italian-French-Spanish, lingua-langue-lengua).
In this case services can help too, it's called REVERSO CONTEXT so, why not sharing knowledge? "Sharing is caring" doesn't involve the virus only! LOL
In my opinion, learning thanks to erotic fiction or generally topics of interest, is a funny way to improve our skills. This world is already full of people building walls, barriers and fighting wars.
As for criticism to plots, erotic fiction is like other kinds of fiction. Everyone has their tastes.
I personally have learnt to read them all, it's a chance to explore new fantasies and know each other's boundaries if you have a partner or fuckbuddies you can trust in.
How could I say "I'm not into watersports" if I didn't try them? But I would behave as judgmental if I didn't read stories about it trying to understand which kind of pleasure it gives.
Have I found something disturbing, here? Of course, an author describing a scene where the top/dominant broke fingers to the bottom. In another story, the bottom drank and the top enjoyed him vomit.
Those particular things disturbed me a lot, and so? What's next?
I simply closed the browser and went to read something else.
Have I received critics? Yes, a couple guys expressed their opinion quite brutally about a story of mine and I simply sent them to fuck off and find something better in life. I don't care about them and keep on writing in free time and easy mood.
Haters won't win. Not from my part. We, authors, should form a network against them, supporting each other in case of heavy hate speech. Community makes it better!