You're not describing meritocracy, which has literally nothing to do with majority conformity, but literally reduces to ability. It's the most unbiased position possible.
There is literally zero unjustified bias in a true meritocracy.
When trying to build a meritocracy, pre-existing bias can certainly skew who has more ability, because some group or other has better access to education or opportunities for acquiring better experience. The solution is not to decry meritocracy, but to enforce those principles even more strongly.
The closest thing to a consensus on programmer productivity is that it's impossible to quantify. How can we objectively predict ability when we don't know how to objectively measure outcomes?
> The closest thing to a consensus on programmer productivity is that it's impossible to quantify
Precision isn't as important as accuracy, and this is achievable. It's difficult, but not impossible.
Assuming that any attempt to change the system necessarily involves hiring/promoting "unqualified" people shows one of those biases: the bias to believe that anyone who does not resemble the existing majority must be "unqualified" or else they'd already have succeeded.
Which is much like the economics joke: an economist and his friend are walking along, and the friend spots a $20 bill on the ground reaches for it. The economist says "that's impossible -- if it really were a $20 bill it would've been picked up by someone else already!"
We know that the old convenient lies -- "people of that race/gender/etc. just aren't as interested in our field" or "evolution shaped their brains to be good at other things, not at this thing" or... well, any of them -- are just that: lies. We know that when a more level playing field is forced upon an industry, suddenly that industry stops looking a lot less white and a lot less male, and further stabs the heart of the "it's a meritocracy" lie.
Promoting the lie of "meritocracy" is, at this point, insupportable and indefensible, no matter who does it or why.