Companies do not desire or seek philosophical diversity, they only want Superficial biologically based "diversity" to prove they have the "correct" philosophy about the world.
It's also a way for banks and other powerful entities to enforce sweeping policies across international businesses that haven't been enacted in law. In other words: if governing bodies aren't working for them, they'll just do it themselves and undermine the will of companies who do not want to participate, by introducing social pressures and boycotting potential partnerships unless they comply.
Ironically, it snuffs out diversity among companies at a 40k foot level.
Specifically, principles that have ultimately led to the great civilizations we're experiencing today, built upon centuries of hard work and deep thinking in both the arts and sciences.
DEI and its creators/pushers are a subtle effort to erase and rebuild this prior work, so that its original creators no longer take credit. Take the movement underway to redefine Math, since its origins are "white". Oh the horror!
The fact that DEI specifically targets "whiteness" is patently racist. Period.
Participating in that is assimilation.
DEI and similar programs use very specific racial language to manipulate everyone into believing whiteness is evil and that rallying around that is the end goal for everyone in a company.
On a similar note, the company has already established certain missions and values that new hires may strongly align with like: "Discovering and enacting the path to safe artificial general intelligence", given not only the excitement around AI's possibilities but also the social responsibility of developing it safely. Both are highly appealing goals that are bound to change humanity forever and it would be monumentally exciting to play a part in that.
Thus, it's safe to think that most employees who are lucky to have earned a chance at participating would want to preserve that, if they're aligned.
This kind of alignment is not the bad thing people think it is. There's nothing quite like a well-oiled machine, even if the perception of diversity from the outside falls by the wayside.
Diversity is too often sought after for vanity, rather than practical purposes. This is the danger of coercive, box-checking ESG goals we're seeing plague companies, to the extent that it's becoming unpopular to chase after due to the strongly partisan political connotations it brings.