There are several reasons:

1. Crypto is more simple than shares market (one can make wallets and buy coins with just a few clicks);
3. One can start with smaller initial capital (only several hundred bucks is enough to enter a promising ICO);
2. Right choice of coins to invest could really bring x100-x1000 profit (not in this downtrend, but hopefully the situation will change);
3. Bigger fluctuations of crypto market give the opportunity for speculators to increase their initial investment several times.