This attitude comes from the reality that it is too easy in many countries to get into the teaching profession. This has come about because of a skewed job market where there are teaching shortages, probably due to the underpaid and overworked nature of the career. So the market has become a market of easy to get onto courses and be in the industry. However, as you point out being a great teacher is a phenomenally difficult task. Perhaps if salaries were increased and working conditions improved the industry can retain the best talent and attract top tier minds, thus changing the attitude towards teachers.
In Finland, school teaching requires a masters degree, even if underpaid. It is not the same everywhere. For me, the whole industry is stagnant and ineffective due to its institutionalised nature. It is definitely an industry that is in need of a good shakeup. It isn't the teachers alone though.