It's fairly typical market psychology. During the capitulation phase investors just want to stop losing money. It can weigh on the psyche to be holding through brutal bear markets.

Of course there is still always the chance we're going to zero, but the chance of us going up by x5 or x10 are also there and it's an asymmetrical risk / reward calculation. Some people are just too risk averse for this type of strategy and would rather just buy on the way up once the perceived risk is gone.