I agree with the quote but in my experience, those people deliberately go out their way to harm others. I would tend to believe those sorts of people have things like NPD. Narcissists can literally lie about you, gas light you into believing you had said or done certain things, turn others against you, destroy your reputation. Do their darndest to destroy your life.
From what you've described about your physics tutor, he was someone you immensely admired. Perhaps even hero worshipped. It's kind of natural then that you hoped he would have a similarly high opinion of you. I experienced the same by the way- a tutor I thought was pretty much God level talented. But, both of us were disappointed when they didn't seem to appreciate us as we'd hoped.
Did he/ they do it deliberately though? Do you feel like he deliberately took you down a peg or, tried to humilate or humble you? Was that done with malice do you suppose?
I tend to think that some people genuinely are toxic. They can't seem to help themselves but hate on others and do all they can to destroy them. It almost seems like a need they have. Not to say it's entirely their fault. Narcissism forms for a reason. But still, I do truly wonder if they can function without being like that. But then, I'm not a fan of determinism either. I still think we have awareness and therefore, choice before we undertake harmful actions.
With our tutors though. I tend to feel like I must admit that it's my fault I had such a hurt reaction. My tutor couldn't help being a genius (in my eyes.) Also- why should they return my admiration? They've taught hundreds of people by now. Many of whom were far more talented than me. Why should they think I was special? What do they owe us? Just because we hero worship them?
Mine didn't exactly put me down but, they massively favoured a friend as it happens. They clearly got on with them far better and, saw something special in them. I was horribly jealous because being good in that subject was so important to me. But, my friend deserved it. They were/ are hugely talented. They also had a very good collaborative work attitude- which I don't. Plus, as a person, they probably just got on better. I think I came across as too weirdly keen to please and impress. That's on me though- not the tutor. My bad reaction in wanting so badly to be praised and liked by someone I rated so highly but being disappointed. That's my feeling anyway.
Some people genuinely go out their way to be toxic. As for others, we may have an insecurity that is inflamed by being around them. Some of course have both going on though so- perhaps you're right- if you believe your tutor actively tried to belittle you.