There seems to be more teacher bashing threads than any other profession on here, it’s disproportionate.
Because everyone has dealings with teachers/schools - both when we were young ourselves and when we have children and maybe grandchildren. So, basically 13 years of your early life and 13 years of your middle age (plus potentially another 13 years if you're an active grandparent doing school runs/plays etc). So out of the average life of say 80 years, you may be "engaged" with teachers/schools for 26+ years of that. That gives you a lot of dealings, and the more dealings, the more likelihood of problems.
Compare with other professions. Very few people have to deal with solicitors, estate agents, accountants, architects, etc more than a handful of times in their lives (if at all). So far fewer dealings, hence less likelihood of problems.
People complain about other professions - there are plenty of threads on here an other fora about slow solicitors, dishonest estate agents, shoddy tradesmen, etc. But fewer people are using them, and for shorter/less frequent events, so obviously there are lower complaints/threads that teachers/schools.
Same with healthcare and the NHS. We all have dealings, and more often, so like teachers/schools, there are lots of complaints on internet fora about GPs, NHS, etc. It stands to reason.