(Public) Education under capital is designed to produce effective workers who can take on management roles without major training. A lot of basic work can be done by someone who cannot read or do advanced maths, but if it took a company months of training to get an employee ready to just balance books or manage a work schedule (or any other task of management). It also trains people to more readily follow orders and not question the system. It is a system built to mold children into more ideal workers under capital, at the expense of the working class instead of the capitalist class.

With the US in the state that it is in, I think it is doubtful that the rich understand why their own system does what it does, and view it as a waste of money that could be laundered instead. So they're attacking the foundations of the society they rule over, because they don't understand/don't care how much it will fuck them over in the long term.