1) they can't buy in to using valuation as their sole investment criteria. They want to be "smarter", thinking they can see things others can't using psychology or charts or other pseudo sciences. 2) They fall sway to Mr Market ( read the Ben graham parable). 3) They can't sell value to clients and only want a strategy clients will pay for. 4) Buffett spends a great deal of time trying to make decisions free of bias. A CFA program teaches you nothing about this, but it's critical to good valuation work. For example, WEB does not want to know the stock price of a company he's analyzing until he's made his valuation estimate. He doesn't want to be biased into giving a too high valuation to a company he loves just to ensure he can buy it.

Lastly, there is a meta level to value investing. A great valuation at a current price isn't enough if the company lacks a competitive moat, or management can't be trusted to treat shareholders well. First level cigar butt value investors never learn this.

Its not an informational asymmetry, it's what you do with it. Walter Schloss is another great example. Beat the market by 5% a year for over 40 years, did it buying exclusively the doggiest public companies. He was the ultimate cigar butt hunter. His advantage wasn't information Wall Street didn't have, it was his willingness to use information Wall Street wouldn't, to invest in opportunities they would not.

Buffett does have one informational edge, his experience and judgement. He knows how value works, he has total confidence it works, and he never panics, even when down 50% in 2008. He never leverages himself in a dangerous manner, never gives someone else control over his decisions.