Managers only hire and reward based on loyalty and threats in these highly political environments. It is very common to see a decent director with very weak managers under him, to ensure that nobody is a threat to his position.
Mediocre corporations work in a very different way from results oriented high performance companies. In mediocre places, games of power rule the place, even if it doesn't make sense economically.
On any given dimension, everyone/everything cannot possibly be above average. If you take competence, most companies will be mediocre. At best you have a bell curve, at worst it's an exponential curve with only a very small amount of high competence.
Hacker News folks tend to see the best side of corporations, working for well managed, innovation driven, purpose oriented places.
It's a privilege. Most corporations are not Google, Apple, Microsoft, Amazon, etc - which a lot of us either work for, or work for companies that were heavily inspired by these top companies.
Yes, past a certain point you are operating to reduce variance.
There's only so many top 1% players, and if you aren't able to pay as well as the GOOG/MSFT/AMZN/AAPLs of the world, then your not going to be able to hire 1000s and 1000s of them.
So most employers are not able to be as selective, especially at scale. Which means they are hiring for B+ players and putting in a lot of "administrivia" to prevent screwups. It's more about hiring for average outcomes and avoiding the downside.
Scrappy startups pre-scale can be an exception in that they have equity and independence to offer to hires in lieu of top tier compensation. Both of those of course are drastically reduced when you have 10s, 100s, 1000s and then 10,000s of employees.
It's not a diss on anyone, so much as the natural order of things.
Even those corporations aren't homogenous in how well they are managed and have a lot of "second class citizen" to whom the privilege doesn't have to apply (managed services, external dev partners, armies of contractors...)