I can see many reasons why some might bristle at getting unsolicited advice, and some of those I can understand. You've essentially got some stranger coming up to you and telling you you're doing something wrong in front of between 2 and 22 other people. Of course that's going to make some people uncomfortable. You don't know them, and they don't know you. Are you being genuinely helpful, or are you just some pretentious know-it-all flexing your own ego? How would they know? Also, why are they failing? Is it assumed that everyone who screws up is just not trying hard enough or just didn't study hard enough? That may be the most likely possibility, but do you really know?
