I'm not sure whether this is sufficient to convince me to stop using the term "meritocracy" — the term is already ingrained in popular usage, irrespective of its provenance, and quite nice in that the word conveys the idea behind it relatively well, so I'm not sure whether the baggage associated with it is sufficiently toxic to justify dropping it.
As for the idea of meritocracy, at least in the narrow sense of selecting people based on their (potential) skills and abilities, I don't really see any better alternatives. The issues of social stratification, lack of inter-generational mobility, unequal access to education, income inequality and self-satisfaction are very severe, but with the partial exception of the last one, I don't agree that they're exacerbated by meritocracy (and regarding the last one, people will always find a reason to be self-satisfied/self-congratulatory).
The problem of political representatives not actually being representative of the population as a whole is indeed worrying. Perhaps sortition [0] might work (???). (If sortition were shown to be functional and implemented, but "meritocracy" continued to be used everywhere else, then meritocracy would become a terrible misnomer...)
[0] https://en.wikipedia.org/wiki/Sortition
As an aside, assuming that the word "meritocracy" was coined in a book satirising the concept, as stated in the article (as well as wikipedia), why did it start being used in a positive sense?