They don’t want to give parents a choice because the parents will “self-select” into segregated
“give a damn about my kids”
and
“don’t give a damn about my kids”
schools.
Those already sending their kids to private schools (even though they would seemingly benefit a lot financially) might be opposed for the following reasons:
1 - Government vouchers will drive up the costs of a private education thus eliminating the most positive benefit (simple supply and demand). Which is exactly what has driven the cost of college through the roof in the last decade or two as government loans and grants have flooded US colleges.
2 - Private schools would be flooded with the rude, ill-behaved, liberally indoctrinated, feral children that private school parents were so desperate to keep their children away from to being with.
When Indianapolis Public Schools had a district “Voucher” program a few years back, the overwhelming majority of parents sent their kids to THE CLOSEST SCHOOL. Simplicity for the PARENTS was the first family priority.
The teachers union, and the Bus Drivers Union threw fits until the program was canceled with the arrival of the new (now almost-gone) superintendent.
A few sent kids to specialty schools, but not very many.