Not one, over fifty.
Whether you never saw it happen does not negate the reality that it does happen.
Whether it happens does not indicate the ubiquity you touted.
If it doesn’t then pray tell how we have so many scientists totally unfamiliar with actual science?
As subjective a metric as I have seen on FR. The big problem with "actual science" is that the amount of work necessary for a PhD precludes breadth. Effectively, the breadth of graduate qualifications are limited by undergraduate work, which is limited by k-12. There is a way to fix that.
Spend some time talking with ex teachers who left the system because they couldn’t deal with this crap.
Given that I write technical books incorporating everything from botany to linguistics, I personally know well over 50 researchers personally, both retired and not. I read tons of current technical papers and probably a book a week. Of their students I see both great work and garbage. Both are spotty. I just don't think such blanket statements hold.
As I said, there are good teachers out there. And with over a decade in the media as a journalist and an editor I interviewed both types across the spectrum. I also personally know a couple that left the field because of that and things every bit as asinine.
When you have a science department that teaches global warming is real, then that’s not science. When you are allowed to google answers, education does not take place. Whether it’s in an elective or the hard ‘sciences’.