I assume you mean they don’t put much stock in the strong EMH - Which is true, but the concept is the underpinning of most risk-weighted investing and some form of it (eg weak or semi-strong EMH) lines up nicely with why index funds outperform on a very broad basis.
I’m trying to think of a good analogy to CS.. maybe “Good engineers don’t put much stock in artificial intelligence”
It's a really approachable theory and contrary to what you'll read in tech message boards - doesn't remotely boil down to "the market can't be wrong". Burton Malkiel (economist most famous for writing "A Random Walk Down Wall St" and being a longtime advisor of Vanguard) has a paper talking about the early 2000's pushback.
It gives a good summation / spells out some critiques / offers his reasons for disagreeing:
