Well, unfortunately, when a school needs a substitute teacher, they have to take what they can get and hope for the best.
The school is about 90% black, hard to find good substitutes. The school gets a rating of 2 out a possible rating of 10 ....
I was proud to be a "travelling substitute". The caliber, backgrounds and skill of my peers was amazing.
Why don't you try substituting in inner city schools and observe what they do, first hand?
I think they do that for many full timers too.