Do they really though? In my experience, school teachers don't really have either and both are either learned on the job or academically taught when pursuing the major. Being a great teacher is tough, but very few teachers are actually great.
Being a university professor is IMO, among the hardest positions to get. In my experience, the smartest people I know are university professors.
If anything, many university professors are grossly underpaid (for what they offer) in exchange for job security and complete freedom to pursue what they love.
Also the original quote was university teaching. The whole professorship and tenure thing is a separate giant ball of complication, and you're right that all that non-teaching stuff is extremely difficult.
Maybe, but this highlights another problem in "soft" careers (social, marketing, teaching etc). It's very hard to objectively qualify candidates. In programming, it's easy: you can program, or not. If you can, the question is likely how fast can you learn new things, and how complex programs you can design & write. Good lawyers win cases. Good traders make money. And so on... How do you compare teachers, marketers (except bullshit "increased engagement by 1600%" claims on their CVs), etc?
But you replace that with a need for a lot more knowledge of teaching and child psychology, so I'd say doing a good job is significantly harder even in the sense of requiring a lot of education.