The percentage of people in academia that aren't socially gifted is probably higher than in other occupations. I don't see any reason why hearing something like that in academia would be more rare.
Social skills weren't lacking that much (don't get me wrong, we were a bunch of weirdos by some standards), but mental health certainly was.
There is a lot of pressure on PhD students and anxiety and/or depression affected all but a handful. Most people go into the programme wanting to be academics afterwards, so you look up to the academics that are there, listen to what they have to say. At the same time a whole lot of your ego is tied up into the success or failure of your work. If somebody shits on your work, that can break you.
I had therapy while in my final year, and so did a bunch of my peers, it's a meat grinder.
My old PhD program's current 5 year graduation rate is way below 50%. I think it's like 10% if you don't count the MD/PhDs that are more likely to get pushed through quickly, but even including them it's not more than 25%. The 6 year graduation rate is barely hitting 50%! I don't know if it's field-dependent or if the Prof was just very out of touch, but graduation in 5 years is an anomaly at this point that actually suggests the person is more likely to have a planned industry (or medical school) exit. Weird to conclude the student is the problem en masse.