This despite that my best known essay is titled "Object Oriented Programming Is An Expensive Disaster Which Must End" a fact the interviewer should know if they'd looked at my resume or spent 10 seconds looking up my name on Google. Wikipedia now lists me as one of the critics of OOP -- https://en.wikipedia.org/wiki/Object-oriented_programming
I'm lucky in that my position is comfortable, so I can laugh off stuff like that, and either educate the person I'm talking to, or end things quickly by explaining that there is probably some kind of cultural mismatch.
But it shows a remarkable laziness on the part of the people who, in theory, want to learn more about me.
The question is, can you whiteboard? They will be testing that. If you can, then all is golden and you probably didn't need to waste those 4-6 years getting that PhD because what you will be working on will have nothing to do with your topic of research (unless it was AI/ML).
If you can demonstrate that you understand programming concepts and can learn, then it's not much more to assume you can write code. If you need someone who can hit the ground running with some specific technology, then you might need to go deep into it, but not to find out if someone can program.
I think you're overthinking the feedback you got.
If it was at one of the big names, they have the luxury of being picky. They can't hire every qualified candidate, so they have to reject most of them. As the interviewer, the company policy likely dictates the interviewer give a reason. Which puts the interviewer in a bind because it implies that there was a good reason for rejecting you. So they'll put canned statements like what you got.
I recently got rejected. And one of the reasons given was something that 3 of the 5 interviewers had explicitly told me they don't care about. I recognized it for what it was - they feel obligated to give some reason, so they nitpick after the fact even though they told you they were not going to nitpick.
When I was younger, I often wondered how it was that New Senior Guy was totally incapable of actually programming, but very good at handwaving and bullshitting, and being patronizing. Now I know how those people got hired. Thanks.
You might as well have said, "Well, you know, when I was a young girl I once had a crush on an older man, and when he rebuffed me I badmouthed him on Insta and all this talk of older men coercing young women in employment is probably just schoolgirl crushes, broken hearts and vindictiveness."
It's true that young people can be cocky and arrogant. But there are unscrupulous people who use this meme to maintain their position, usually to the detriment of the young people. If your interview system is unable to identify such people then you will create a hostile environment. Hopefully, your good people will leave. Unfortunately, many will stay and blame or doubt themselves. I was very lucky in two cases to be at a start-up with a strong CEO who wanted to see results (which I could produce, but which the bullshitter could not).
I was also lucky that in those two cases, the CEO correctly interpreted my emotional expression, which ran the gamut of anger, isolation, helplessness, victimhood, righteousness, denial, negotiation, not as a lunatic but as someone in a fundamentally awful position, and why.
So in one specific case I'm thinking of, the senior guy in question tanked two consecutive projects and lost a major client, while in another, the CEO eventually called him out by asking to demonstrate doing himself what he claimed he was mentoring his team on, and firing him when he failed (the guy handwaved, boasted, and prevaricated but couldn't actually do what was asked). That CEO was fucking great.
For candidates with many years of experience, obviously they can and have been writing software effectively, so for me it mostly comes down to whether they could work well on a team, interact with clients successfully, and be capable of mentoring juniors.