Other country, other situation, but I think this meta observation works for both:

If the educational system is broken too much, the society loses an ability to rationally discuss how to fix it, because the "unbelievable" facts you report are taken as an evidence against your sanity or honesty, not against the system. And of course there are some people who benefit from the system remaining as it is, and they are happy to confirm that you are wrong.

On some level, yeah, extraordinary claims require extraordinary evidence. But people have their priors seriously wrong here -- sanity waterline is generally low, incompetence is not so rare in the absence of feedback, and there are lot of money to make by abusing the school system. Also the prior probabilities are counted repeatedly. (If one teacher complains, he is probabably just an incompetent lunatic. If another teacher complains, she is also an incompetent lunatic. If thousands of teachers complain... well, by the same logic, they are all incompetent lunatics. There is never a point where there is enough evidence to start suspecting that they might actually be right. It also does not promote honest communication if it is widely known that a teacher who complains about the system will be considered incompetent.)

EDIT: I was a teacher for a few years, then I realized the system is so broken that my individual contribution as a teacher is unlikely to improve things. I talked to some people around me about what I have experienced. Later one of them told me that at the beginning they just considered me crazy, because obviously things can't be that wrong. But they were curious whether the things I said could be at least partially true, so they cross-checked some of my stories with other teachers. And the other teachers confirmed my version. Even now the person tells me it is impossible to believe everything I said (only a few things could be cross-checked), but the confirmation from the other sources at least moved my credibility from "crazy" to "essentially correct, but probably exaggerating a lot" area. I asked whether they consider the other teachers (who have confirmed my stories) to be similarly untrustworthy as me, and the answer was negative. Apparently the greatest difference is that I spread the information actively, but the other ones were silent and only answered when they were asked. They have better social skills than me, and probably soon realized that speaking about their experience is only going to ruin their credibility. (If you are asked about an improbable thing and you confirm it, it does not have the same impact as when you contribute dozen improbable stories to an unprepared audience.)