In addition to the need for approval there is also just the nature of the Internet itself, which strips communication of non-verbal cues, like tone and facial expression, so there’s lots of potential for miscommunication there.
If you’re trying to make a bold statement that is unequivocal it can often come across to other people as being harsh or an attack, and if you are making a broad statement about groups as they relate to social hierarchy people often misconstrue that as a personal attack.
But I imagine it gets frustrating having to deal with the “not all men,” “not all white people” response all the time.