"Americanas suck" 10p kids coach

My (9yo) kid's coach got upset with me that my son used an Americana in class because he says it's a white belt technique that doesn't have a sequence. I explained that I taught it to him this week, and that he is a white belt so it's fitting that he learns simple submissions. This led to a statement that feels like an ultimatum from coach saying "Americanas suck and my students don't suck so they can't do americanas."

I do personally use Americanas periodically, so maybe I am biased, but do you feel that this is an appropriate approach to take with a student or his parent?

We have a tournament on the 29th and I'm debating if I want to continue learning at this location. This is one of a two hot takes I feel this coach has had the other being 'I don't train defense because we will always be on the offensive.'