Saysme, it’s pretty endemic to the frum education system that teachers either don’t know or are afraid to answer legitimate questions (and with the history of backlash, I don’t blame them for being afraid…) The reality is that lots of people say similar things about bais yakovs and yeshivas. The people running them (and their defenders) are free to ignore the complaints – after all, the OTD kids don’t care and this is the system that the gedolim instituted so it can’t have any flaws and if it appears to that is because the observers are mistaken.
But the option is also there to listen to the complaints, think through them open-mindedly and critically, and perhaps achieve some meaningful improvement that way.