I am a teacher, and I will offer a couple observations on my 'experience' of this job, decades apart in two radically different places.
A) Massachusetts, 1994ish. Tried but failed to get an entry level teaching job with a M.Ed. granted from UMass. The problem was that I didn't have a car (absolutely couldn't afford), and maybe you know about rents in Boston (which were about to climb yet again due to 1995's abolition of rent control). It was much more lucrative to be a temp worker/typist than to work in teaching. There were so many people who wanted to teach inside Route 128 ... it was hopeless. This didn't mean teachers were well paid, nor terribly 'good,' just that the job was very political. I eventually got work through my mom, who was a 15 year teacher in suburban system.
B) New Mexico, 2014. If you have a degree, you can basically walk onto a job if you hustle a little (or know someone, and this is a small state). We have a teacher shortage, and so there is a 'provisional license' step where you get a temp license, and have to start taking education classes. Around here the pay ain't great, but NM isn't expensive, and a teacher's salary is livable (which it is NOT in Mass these days).
Where the bar gets lowered is in a couple of places, primarily the teacher-training classes given to provisional licensees. They aren't low-quality, it's just that if YOU are a low-quality student, you're not likely to be failed.
One thing that strikes me is how similar are the teachers I encountered in the moneyed, education-valuing, test-score-acing haven of Massachusetts, and the comparatively poorer, scrappier, more blue-collar environs of New Mexico. They're a lot alike.
The problem is that so few people want the job any more, and can you blame them? Teaching is a terribly hard job, and the hours are atrocious. Pay (here) is OK, but if you do not have a strong sense of mission, I just can't see why you'd do it.