While it wasn't teaching about capitalism explicitly, it says:

"...the children were building their assumptions about ownership and the social power it conveys — assumptions that mirrored those of a class-based, capitalist society — a society that we teachers believe to be unjust and oppressive."

In my experience, it is far more common for people to take issue with the classism within out capitalistic society than with capitalism itself.

Is is disheartening that any critique of power, class or ownership becomes synonymous with being anticapitalist. These seem like crucial topics to discuss if you want a well functioning capitalist society.

Agreed. Ironically I find many capitalists aren't really capitalists at all. They want socialism for the rich.