This is true, but I don't think it's relevant. Those who can't afford the table stakes aren't represented, and while that's a bad thing in general, it doesn't cause the specific internal resentment within the project that the earlier post was talking about. I think "meritocracy" in this case was used to refer to the internal social dynamics of this system, not the generalised ones that apply across the whole population.

In other words, I think this reply shifts the context from "will paying volunteers harm the project?" to "is paying volunteers morally right because it enables wider participation?"