Most traders quit because they are unable to obtain profits this way, and it is not surprising at all as trading is too hard and requires a great deal of skill for any profits to come, the issue is that becoming an investor can be very difficult for those former traders too, and that is because they are used to react to any movement on the markets and buy and sell coins based on those short term movements, while an investor needs to be way more resistant to that volatility and avoid making any kind of move based on it.