He [Muhammad] declared undistinguishing and exterminating war, as a part of his religion, against all the rest of mankind…The precept of the Koran is, perpetual war against all who deny, that Mahomet is the prophet of God.
Horse sense is the thing a horse has which keeps it from betting on people. ~W.C. Fields
Hey, I agree with you here, at least in principle.
But the problem may be the strings that are attached to those vouchers.
I went to a large private (Catholic) university. They were good in business, law, the liberal arts, and the more business oriented forms of computer science and information technology. But they were mediocre in the hard sciences, with a faculty that did not have the gravitas or stature of some of the other departments. And while being a really large, old, established university in one of the largest cities in the country - unlike other peer universities of equal stature they did not do any appreciable scientific research! That lack of researched jumped right-out to anyone that ever worked or studied seriously in the sciences.
I finally approached one of the senior high-ranking science faculty about this lack-of-research anomaly. Here's what he said:
They decided to forgo any federal research funding, because if they accept just one dollar of fed funding they'll be subject to a gazillion federal regulations. They did not want the feds telling them who to accept, they did not want to fill any quotas or any other standards, nor be told how to run the research they did. They believed in accepting a portion of students from underprivileged backgrounds, but preferred to make their decisions looking at the prospective students one-on-one basis, in a multidimensional holistic manner, rather than the more simplistic way the government mandates.
Accepting under-privileged research students under the gov's terms, was only one facet of government regulations they didn't want to have pushed down their throats. There were others, but I'm giving you a prominent example. Having attended this school, I saw the environment they fostered and I'm not sure I can argue against them. It was a great environment!
This was a long time ago, and maybe they eventually changed. But once you take government money, you open yourself up to a plethora of possible consequences.
TL;DR once you take gov money they control you