That doesn't mean the teachers support vouchers. It does seem to prove that, if your job is on the line, you may increase your effort to improve your performance. Without the pressure of competition, it's too easy to choose other priorities and the comfort of continuing to do things the way you have always done them. I am a strong advocate of educational choice. If vouchers will get the job done, I'll support them.
Tuition opens the entire system immediately to full and fair competition.
It makes it possible for entrepreneurs to begin competing immediately for your educational business. Choice makes it possible for the market to decide who does and does not provide the quality needed. It immediately frees the children who are now trapped in inadequate schools. My guess is that the full cost of an excellent education will be considerably less than it is now.