As
@rulerkk put it nicely, it's the way in which it was said. The sentence said "are you
really willing to avoid certain specialties that may be your passion because of sleep?"
You don't get that statement is leading and minimizing at the same time? Picture the sentence written this way: "are you
really not going to come in to round on 20 patients because you have a fever of 104?" The sentence is stated in a way in which there is only one right answer or else it's a bad idea.
The sentence on its own is not toxic and I don't think anyone said it was. It's the mentality behind it that's toxic and that mentality can be inferred in the way in which it's stated. It suggests sleep is not an important enough reason to prevent you from picking the specialty you want (in fact, you can pick the specialty you want in many cases and STILL protect your sleep) and that type of thinking is part of the toxic culture of medicine.
Has nothing to do with us being offended. Frankly, I couldn't care less as I'm an attending blissfully happy in my choices. But calling out the problematic mentality is fair game.