I'm a capitalist for one reason: to raise living standards in my community. A familiar mantra of capitalism guides me: Markets are powerful and efficient.
I'm also a realist, so I temper that mantra: Markets are powerful and efficient. And markets fail.
Market failure is an established, well-understood field of study in mainstream economics. Generations of economists accept the basics of market failure.
However, American economists turn their heads away at the mention of it, because it sounds like heresy.