Nope, just courteous.
* People who don’t have flawless grammar are more likely to use AI to write on social media.
* Perhaps such people did not learn English as their first language and hence are more likely to belong to a minority group — so it’s racist to be upset about them using AI.
* Perhaps such people may not be as educated or as intelligent as someone with flawless grammar — so it’s elitist to be upset about them using AI.
People judge you based on your grammar all the time. AI removes this signal, which is why people get upset.