Let's be honest, I don't think even you believe that, you're just saying it to be a dick. I get it. Furthermore you're either making it up or you just don't know that being an Entertainer is important to being a teacher. If you can't engage a classroom, if you're not personable, if you can't hold their interest you probably won't be that successful. Another thing I doubt you understand is that the curriculum has been set in stone probably for years. A quick scan of this week's lesson plan anybody should be able to discuss it. With or without a degree.
There are a lot more factors that go into entertaining than vocal talent that you probably don't understand because of your obsession with rote learning.
WSS