When I was a kid there was one lunch choice: eat what they had or bring your own. It seems to me that adding more choices would increase costs, veggie or no. Should schools start offering an Adkins diet (almost all meat) choice just because a few kids want that? If you want a special meal, bring it, don’t make the whole school provide for your dietary quirks.
If the options are economically feasible, they should offer them.
As someone else pointed out, if the schools could actually turn a profit selling caviar (though this seems highly unlikely) they should.
Again, all my arguments are based on the assumption that the veggie meals are economically feasible. If they are not, then they shouldn’t be offered.
You seem to have a totally irrational aversion to offering them, even if they are economically feasible.
Even in a government run enterprise, the more like a free market you make it, the better it will be.