We know[1] that a more diverse group creates better group outcomes than a non-diverse group where specific individuals may have better performance. Even from a wholly selfish perspective for the people running a project, prizing diversity of qualified individuals over a pure meritocracy is the right play.
From a "making the world a better place" perspective where some altruism is shown, it also helps to acknowledge that not everyone has all the same advantages and tailwinds so that it is fundamentally more difficult for them to have had all the same opportunities and advantages, and providing those opportunities and advantages to them gives them that chance to even the playing field. The amount of unconscious bias built in to humans also means it is difficult for us to be effective judges of ability for those that are not like us. You don't have to be racist/exist/homophobic/transphobic/etc. to have built in biases - you just have to be human. They're difficult to overcome without explicitly stating goals around it.
[1] https://scholar.google.com/scholar?hl=en&as_sdt=0,44&as_vis=...
> The result of [social] categorization processes may be that work groups function more smoothly when they are homogeneous than when they are more diverse … This analysis is corroborated by findings of, for instance, higher group cohesion (e.g., O'Reilly et al. 1989), lower turnover (e.g., Wagner et al. 1984), and higher performance (e.g., Murnighan & Conlon 1991) in more homogeneous groups …
> In contrast to the social categorization (and similarity/attraction) perspective, the information/decision-making perspective emphasizes the positive effects of work group diversity. The starting point for this perspective is the notion that diverse groups are likely to possess a broader range of task-relevant knowledge, skills, and abilities, and members with different opinions and perspectives … Corroborating this analysis, some studies find an association of diversity with higher performance and innovation (e.g., Bantel & Jackson 1989).
> In their simplest form (a main effect of diversity), neither analysis is supported. Evidence for the positive effects as well as for the negative effects of diversity is highly inconsistent (Bowers et al. 2000, Webber & Donahue 2001, Williams & O'Reilly 1998) and raises the question of whether, and how, the perspectives on the positive and the negative effects of diversity can be reconciled and integrated.
The case for workplace diversity needs to be argued on social justice principles, because there isn’t enough evidence for the economic efficiency argument.
No one is saying ban the word meritocracy, but people are saying that if you're arguing for one, you've missed the point.
But for a while, the UK actually didn't do that. New universities were created, "grammar schools" were mostly replaced, new hiring practices adopted, and the stranglehold of the establishment was broken a little bit, for a little while.
That was because as ridiculous as the original idea might have been, good people with good intentions started to believe in "meritocracy", and used the idea to make changes.
And, yes, I believe the world would be a better place if we followed these rules with many projects regardless of the field.
Btw, there are some interesting facts about the history of the word, "meritocracy": https://en.m.wikipedia.org/wiki/The_Rise_of_the_Meritocracy#....