Having worked at a big tech company, I can report that there is an intense, career-making-or-breaking individual imperative for managers to prove the 'value' of soft assets like credibility or popularity.
In my opinion, the reason these companies are willing to shed vast amounts of credibility for cents on the dollar is a systematic mistaking of asset dividends for asset value, which is reified into the organizational culture -- because no one in the C-suite really knows better, not-knowing is selected for, and ultimately becomes a requirement for individual careers to progress.
The dynamic is easier to see in other parts of the economy. While the rent that a fancy house can earn, say, does in fact speak to the value of that house, the fact that it is available for rent in the first place also impacts the value. For literal houses, this offset can be overcome, but for something like your credibility or your integrity, it's lethal.
But that doesn't matter if your boss doesn't know this. All that they see is 'number go up'. Then, often, your number -- be it salary or rank or both - goes up too. And six months later, when the consequences of the firesale become clear, it's too late for the employer -- but not for you, the architect of this terrible idea! You've already augmented your own income, and you can go back on the job market asking for equal-or-better compensation.
Since the number of companies suffering from this acculturated cognitive bias is greater than 1, you can in effect ping-pong between two such companies while gutting both, making larger and larger paycheques with each bounce.
This process is even easier if you work for a really big company, because then you don't even have to change employers! You can just change divisions every six months. The next reorg is right around the corner.
Credibility-for-sale is apoptosis, pure and clean, and it's lucrative to induce, even by accident.