Earlier quoted context omitted.
The real problem is people studying bullshit that nobody really needs. Young people got sold the idea that they can be anything they want to be, they they are all special snowflakes. The reality is quite a bit more brutal. What we really need is mandatory career counseling, once a year, for every student. The counselors must be familiar with the state of the market, the market trends, technology trends, number of fut…
There's also the problem across the aisle of employers looking for bullshit skills and experience that are almost completely irrelevant to the jobs they're offering. Graduating from college today and trying to move into the workforce feels like a lockout, like there's some sort of employer union to purposefully bar recent grads out of employment. It really has nothing to do with studying "bullshit degrees", as so man…
If your premise is true and any employer with competitors did this systematically they would be subjecting themselves to a significant competitive disadvantage. You're postulating that employers in general voluntarily ignore their own best interests. Some companies may be this mismanaged, but suggesting that the market as a whole is this incompetent is quite a stretch.
Rather, it's likely that employers have some incentive to put up these seemingly arbitrary bars of experience. Perhaps they're mitigating risks (e.g. of high turnover) or they have trouble filtering the candidate pool to a manageable size with other qualifications.