>Meritocracy is seen, universally, as a good thing - the people who work the hardest get the most
As far as I know, when the term was coined by Michael Young it was not intended to be a positive at all. To me it's strange that people see it as a positive, even in the theoretical principle, which for better or worse never actually manifests itself in real life.
Meritocracy turns out to be a lot like the harm principle - it is in a sense "hollow"[0], a principle which everyone would agree with, and to be used like a vessel to carry existing ideas (the definition of merit, absence of the effect of societal and external factors, that those with more merit can and will use their power wisely and justly etc.), which are taken as givens; any existing structure is deemed to be constructed through merit if the person advocating meritocracy is well positioned within it. A structure is not meritocratic if the person is not positioned well within it. Its proponents continually add ad-hoc specifications to the conception of merit.
For instance, when people point out that those who work hard aren't at the top, the response is "working hard is not working smart, and only working smart has merit", even in cases where there is little scope to "work smart".
When people point out that merit is hard or even impossible to objectively quantify in the case of several branches of a project that depend on each other, the response is that certain branches of the project (usually the factors the respondee is responsible for) are more worthy of merit than others.
When people point out that the concept of pure equality of opportunity is untenable because it requires correcting discrimination already in society, and that new inequalities arise with regard to ownership of assets even if everyone starts off with the same, the response is that the system is already set up the way it ought to be and we shouldn't worry about the process by which merit is accrued.
[0] Smith, Steven Douglas, The Hollowness of the Harm Principle (September 2004). U San Diego Legal Studies Research Paper No. 05-07.