Stephen Jay Gould, a great biologist, once said that "I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops."
I think your comment shows a profund misunderstanding of what meritocracy means. No one is saying everyone is equally capable. Merit, ability, knowledge, are all true and real. A meritocracy is a system where those who posses them triumph over those that do not. We do not live in a system like that, and as I mentioned its probably good we do not as the ethics of such a system are quite awful.
I just used credentials to defend against the personal attack that was implying the only people against meritocracy are those with nothing to offer.