It's not necessary to spell out in the contract what the legal requirements are.
The words "exploitative" and "treated well" are very fuzzy words, and everyone has a different idea of what they mean.
> for all sorts of evil reasons
Then the employee can press charges or sue.
> regulating down wages
How that works out in the real world is companies cheat on these cartels. Remember when Jobs complained that Google was violating their "no poaching" agreement? Cartels are unstable and unable to enforce their cartels, so they don't really work.
Nadella does not need to justify his layoffs. If they don't fit into Microsoft's plans, they get laid off. Microsoft does not owe them a job. BTW, I know many people who have left Microsoft for a panoply of reasons. Many went to other companies, many started their own, some succeeded, some didn't, some went back to Microsoft. It's a chaotic, dynamic system. I also know some that made incredible fortunes off of their stock options. How horrible that Microsoft minted tens of thousands of multimillionaires out of their employees! Some even into 9 figures. What a hell-hole! Microsoft is probably the worst example you could mention as an evil employer.
Dummy me that didn't get hired on by MSFT in the 1980s. Or I shoulda invested everything I had into MSFT stock. When I went to the doc for a catscan, I asked the operator to set the dial to 1987 so I could tell my foolish earlier self to buy buy buy MSFT! Sadly, the catscan machine had the side effect of wiping my memory of the trip.
> You can argue whether this is good or bad
It's bad, because it makes businesses highly reluctant to hire people, which makes the economy less prosperous.