I think adoption is a very gradual steady curve up(BTC has stagnated, probably reversed). The price returns to this mean after getting over bought.
That's what a trader says. Traders totally ignore the fundamentals that create why there is value in the first place and what affects the value.
BCH utility increases with adoption. Obviously that's going to be a much more gradual curve than the Wild price swings.
The definition of overbought is when the price is higher than the current utility(and therefore demand). That has nothing to do with trading.
BTC's utility crashed. Therefore the market crashed. If it didn't there wouldn't even be BCH. It crashed because the utility crashed, not because it was overbought.
