As to a specific number, my gut feeling tells me $28K seems rather excessive. That's more money annually than I and most of my friends made in total yearly wages for a good chunk of our adult lives, and we all worked rather dutifully. I'm not entirely convinced that the creation of art requires such sums. And $28k could certainly help a lot of other children in need.
In any case, I'd like to think one of the most satisfying aspects of parenting is watching a child transform into an adult, I'm unsure whether a perpetual yearly stipend equal to the wages of large segments of this country is the best method to achieve that goal. But assuming my child was the recipient of such privilege, I'd hope I would have taught them the humility to understand just how privileged they were, and in general refrain from criticism based on generalities.