Great points.
In addition, fruitless labour does it fine. This happened mostly where a newbie is introduced to bounty and airdrops, after weeks snd weeks of feeling forms without seeing result he or she may give up. I mean its disheartening, seeing lots of ICO, bounties and airdrops are fake.
Depreciation in value with no stop loss tech in place.
Manual trading and complexity of trade.
Hackers and rumour of hackers is another factor. Can you believe this, just last week a guy hacked my bitmex, next. Exchange, stocks. Ex and two other trading platform. All was done within one hour. Believe me, I have 2FA enabled.
These and lots more had/are forced/forcing people out of trade.