Merit deserves reward. Not necessarily simple financial reward (though there's nothing unreasonable about earning a lot of money) but sincething of value to the meritorious person, to reflect the effort and excellence of human time commited.
Meritocracy is a worthy ideal for society as it includes the concept of merit duly rewarded but writ large across a community where all citizens are rewarded for effort and excellence, the size of the reward being an objective reflection of that effort and excellence relative to others. The end result, in a civilized fair society, is to encourage the best to rise to the top, the least talented, most indolent to sink to the baseline.
Socialism gets criticized for being systemically bad for effort and merit because the more a society tries to impose equality of outcome, the more it elevates the least productive, poirest citizens above their effort and excellence, the less socialist Sudbury is a meritocracy. The best and the brightest underperform because their exceptional effort and excellence makes little difference to their gain relative to the uplifted plebian.
Corporate capitalism is criticized for being a form of corrupted capitalism where monopoly, oligarchy and protectionist top-down regulation to stack the deck in favour of the wealthy and the powerful ends up destroying incentives, preventing merit from gaining its reward for effort and excellence.
All political systems that limit freedom of the individual are also bad for meritocracy because the loss of liberty devalues life and the authoritarian imposition of jobs on citizens turns them into subordinates of governing power. Personal gain from effort and excellence loses its capital value and there's only so far social brownie points bestowed by authority can satisfy - or motivate.