The only way quants can make money is from active traders on the other side. It's impossible for quants to make money off buy and hold index investors. If everyone took your advice (and I do), there'd be no such thing as quants
The typical self-described "buy and hold investor" I know is actually a "buy and hold then panic and sell" investor. Take a look at r/investing to see what I'm talking about. I'm not criticizing them per se; it's unnerving to imagine half your life savings or retirement being gone in a flash.
Since when is /r/investing a buy-and-hold type of place? Those guys live at /r/personalfinance.