Leaving aside whether the statistics posted in this article are an issue of meritocracy, the problems with meritocracy itself are quite well documented. Do you want to select for "best" or "would turn out best under optimal conditions"? Meritocracy typically selects for the former, not the latter; it highlights those who shine, and ignores those who have not had an opportunity to shine.

Also see https://news.ycombinator.com/item?id=8534078 for another issue with focusing only on the highlights of an entire community.