What's your argument?

The argument is that the previous system wasn't a meritocracy either, and by accounting for the existing biases we gather up the talent that was previously ignored.

You don't stop reading the resume upon hitting <minority group> and hit the hire button. They still need the other required skills too.

> The argument is that the previous system wasn't a meritocracy either, and by accounting for the existing biases we gather up the talent that was previously ignored.

Whether or not that is true (you haven't given evidence for it), this doesn't justify introducing even more anti-meritocratic practices like diversity hiring. Two wrongs don't make a right.

> You don't stop reading the resume upon hitting <minority group> and hit the hire button. They still need the other required skills too.

An analogous argument wouldn't justify e.g. nepotism ("we don't care only about nepotism, we also care partly about merit!") and it doesn't justify diversity hiring either. The argument is that, when deciding who should hired for doing a difficult cancer surgery, only merit should be considered, and diversity (or nepotism etc) shouldn't play any role at all.

The previous system wasn't just not a meritocracy, it was famously discriminatory. And not just against gay or black people - poor and disabled white people were discriminated against too. Not to mention rampant nepotism and favouritism, which the anti-DEI crowd don't seem to care as much about.