There's two economic arguments that slightly clash here about student fees. Some say that education is a public good (having lots of educated people around benefits everyone) and should therefore be subsidized from taxes.
The other is that students benefit in higher pay later so they should be the ones who pay. MBA programs are, as you point out, an extreme of this.
What has been happening with first degrees is that, in the UK say, possession of an arts degree does not raise your pay at all. So it's very hard to say that the student should pay: but equally, if an arts degree adds no value, why the tax subsidy?
MBA programs will I think always stay outside of such political calculations. For any subsidy to students would appear to be subsidies to business: not something politically viable in most countries.