I see lower-ranked members posting in lousy English and most likely only to get paid for whatever signature campaign they're in.
I'm one of those in this Forum that has gotten merits from you which I'm grateful for but when you talk about lower ranked members posting in lousy English, I feel that's how they know. With time some might adjust, many can't use English correctly like you do simply because they are not good at speaking English, is not their mother tongue. That's the area you're better than they are and I believe learning is a process, when you give them time they'll improve swiftly, is just to believe and to put more effort.
If people can spend decent effort of writing to express their opinion, language surely is not main barrier for discussion in this forum, especially nowadays with efficient support from many tools for content generation as well as grammar, spelling checks and so on.
In addition, if they feel like their English is not good enough, they can simply post in their local boards with mother tongue that just fine.
I believe that's another reason why some members make use of AI to publish their English which I some how don't blame them because some members don't know how to handle some of these corrections that looks like blasting, it's hard to take in by some users.
If you say they should post in their local board if English isn't good for them are you saying that they should avoid other boards that are English related? And be posting only in their local board? Bro is not suppose to be, then why is it called a community?
If so how can they learn if they are always indoors as in inside where they only have their own (where they have those speaking same language), is not suppose to be. To me is best to correct them via PM or when you quote them if there are any errors you make it bold and correct the mistake then continue posting, that can help and it will change how they think and you'd see more who wants their English to be as good as possible.