Isn't it just math? How many PhD students are "minted" by a professor over their career? A very crude estimate is between 10 and 50. For each PhD to get a professorship, each generation the number of jobs would have to multiply by that number. Does anyone believe that can be possible? If not, you will end up with a "crisis" like this, regardless of the best of intentions or evil influences or whatever. I mean of course if you kept 10x-ing the available jobs, at some point the supply of students would thin out but probably only at a huge number.