Apologies: have not had time to RT whole FT. I've followed some of the school threads. What I've seen hasn't been a wholesale bashing of teachers per se, but has certainly been extremely critical of governmental policy, with which schools are duty-bound to comply.
Frustration on many occasions seems to stem from a focus on trivial issues. I..e the colour of the stitching on a child's shoes; the policing of their lunchbox contents (whilst giving them ketchup and cordial with school lunches); the jurisdiction or otherwise for parents to take their DC out of school for reasons they deem appropriate. Meantime, really serious issues are ignored. A prime example is the problem of bullying, the laying down of detailed, intricate policies to stamp this out, and the frequency of rugsweeping as the preferred method of dealing with it as opposed to adhering to their own policies.
Teaching to test, browbeating them with phonics, the obsession with SATs, meeting attendance targets with discriminatory incentives, etc, are other areas of criticism. And they often frustrate teachers in equal measure.
Teaching, like many other public sector professions, is stymied by red tape and this is all imposed at policy level. Granted, some teachers do impose this stuff more gleefully than others, and there are many very dedicated, talented teachers out there who do do an amazing job. But for the most part, what I see on this is mostly criticism of a system as opposed to individuals.
It's justified. The system has gone very badly wrong and is failing generations of children. And yes, I'm educator; in my case a university lecturer, who sees at first-hand the mess that frequently comes out at the other end of the schools. (Not, I hasten to add, the kids' fault. They can only work with what is put in front of them).
GCSEs and A Levels (I've taught both in the past) have been dumbed down. I'm afraid that's undeniable.