You're right, one needs to be able to take criticism, not about the code, but in everything, however being able to give criticism correctly is equally important.

This is not about style (kind or to the point, or in any style), but again about keeping in mind that you're talking with a human being.

You can say "This doesn't work (because of this), so do it this way", in thousand different intonations, and you can add the underlying message in anywhere on the spectrum of "this works better for our case" to "you're a triple distilled idiot".

This is not about being sensitive or having a skin, this is about mutual respect in a professional setting. When you do your to the point, brutal criticism, you cannot hurt the other party if you keep in mind that you are talking with a human being.

During my M.Sc. jury, one member called me a liar, and my professor had to intervene politely yet forcefully, and in my Ph.D. jury one member flat out insulted me, yet I defended myself politely yet forcefully.

They could have said the same thing, with the same words, in a much politer tone, but they preferred to attack me directly instead of attacking my work, so there's that.

I tend to give direct criticisms as well, yet I do my best to make sure that it's plain and simple I'm trying to guide and it's about the work, not about the person.

Because, I do not do anything to anyone which I don't want to experience myself.