After reflection on my own experience going through the public school system, I've realized that the absence of the prototypical religion in public schools did not by any means remove "proselytizing and indoctrination". Instead, a sort of undefined religion has emerged, that we'll likely only be able to encapsulate in the rear-view mirror of history.
The most obvious form of proselytization, to me, was the constant preaching about college. While a rabbit-hole on its own, college attendance has not been leading to good outcomes for many of its attendees in recent times, and seems to have been an unquestionable tenet.
Simply put, secular public schools are not devoid of proselytizing and indoctrination. Why withhold taxpayers the option to choose their preferred form of indoctrination for their kids?
This prohibits discriminating against parents for how they want to raise their children.
I live in Washington, DC, where there is no such provision. But I'd be as reluctant to see the tax dollars go to Washington International School or Georgetown Day School as I would to Sidwell Friends or Gonzaga.
I honestly don't see why there is an attempt to create outrage here. If the people of Montana, via their democratically-elected representatives, see fit to offer this scholarship program then why is this so wrong?
The first amendment is only necessary protection for minority rights. What is freedom of religion if you can't have freedom from religion?
I live in Utah, where The Corporation for the President of the Church of Jesus Christ of Later-day Saints (the mainstream Mormon Church) has an overtly significant voice in politics and media. Its private university Brigham Young University likely benefits significantly from this situation, which is totally unnecessary, since the church itself has plenty of funding available, including a 501c3 tax-exempt $124 billion+ liquid investment account built from tithing donations in excess if $7 billion per year.
I don't want to see a penny of my country or state's tax dollars going to a university named after a man who, as a self-proclaimed prophet of God, taught that interracial marriage is to be punished by death on the spot, and does not allow students to be in same-sex relationships, or leave their religion before graduation.
I don't see this as an attempt to create outrage, but to express that which already exists.