We are now in an age where expected norms in society are such that the slightest criticism of anyone—even if justified—is taken as offensive by both the recipient and by onlookers.
Unfortunately, keeping mum and not saying anything just lets people off the hook, they no longer have to justify their actions either to themselves or anyone else. In fact, I'd argue that in recent years the trend has gotten so bad and out of hand that it's having a very noticeable negative impact on society.
Clearly, I'm older than you, when I was younger this comment would have hardly raised an eyebrow (right, I'm old enough to have noticed this societal change and the negative impact it's had).
When I was at school we were actively taught to ignore unwarranted critism, and even if it were justified to consider carefully what was actually said before responding. In fact, the old adage that 'sticks and stones may break my bones but words will never hurt me' was drummed into us kids at a very early age (in infants school). Can you imagin teachers teaching that today? I'd reckon they'd likely be lynched.
Now, what's the situation nowadays when kids are no longer taught how to develop and strengthen their resilience? Well, one only has to look at the fallout on social media. Now we have kids taking such great offense at something someone has said to them and they're getting upset to such an extent that some even resort to suicide. (When I was a kid suicide was something that only adults with disturbed minds did—never kids or teenagers, it was unheard of. No doubt there were isolated instances but we kids never heard of them.)