I'm no economist, but I don't quite agree with that statement. A business is considered "healthy" only if it is growing, and if its profit gets larger from one year to the next. It doesn't take a PhD to know that that type of growth is not natural, and aking to cancerous. So it's not that capitalism is based on the statement, but that success in business is.
Definitely not black and white.
This guy is an educated dood but is a teacher so he won't necessarily be that much more experienced in finances as he most likely teaches kids and works for a union. Still, questioning our actions within the capitalist system is a good self check as many will take more than their share by orders of magnitude just because the system perpetuates it.