It's not actually illegal. For it to be actually illegal, governments would have to enforce the laws but they don't. Left wing governments can't get rid of the laws but they can easily appoint woke allies to enforcement positions, to ensure the law is only enforced in one direction.

I've been in a company all hands, which was broadcast to the whole multi-office company via video link, where the CEO himself announced that the next person to fill a very senior executive role had to be a woman and it would remain empty for as long as it took to do that. Did he care that he just admitted the company would break the law, on video? No because it's not illegal, it's outright encouraged.

Fundamentally, you cannot have left wing people in charge of enforcing equality rules, whether it be legislation or company policies. They point blank will not do it because they think that handing women or racial minorities unique powers is the most morally virtuous thing they can do, and that the system they're tasked with enforcing is immoral.

It may or may not be legal but it opens the corporation up to stockholder lawsuits. Once a corporation begins hiring on criteria unrelated to maximizing stockholder income they've gone down a path that will bring down management.

DEI initiatives harm corporations long-term and will always ultimately fail because the corporation is no longer maximizing profits. This is not a new idea: IIRC even Adam Smith had something to say about such kind of activity.

Yes in theory, no in practice. Such lawsuits are incredibly rare, and this sort of thing is often done with the explicit acquiescence of the board anyway! And in many places they just change the law to explicitly make it legal, like in the UK, where they passed an Equality Act actually makes discrimination legal.

Yes it harms corporations in both long and short term but the people who do it don't care, because their moral code states that corporate harm either isn't real or is actually a good thing. You can't win when arguing with someone's fundamental moral code.