Not the crypto is dangerous, dangerous is trading. Recently i thought that crypto dangerous for banks, but actually, it's not. Banks will *buy* that technology, as they print money and suck money from the people. Trading is dangerous for us more than banks 
What you have said is bullshit. What will happen if we stop trading? TRADING is dangerous?! Making money is not child's play. Trading is always risky. If you dont understand how to trade you need to learn first. No trading means zero volume, means dead coins.
And what do you want to say about printing money and blockchain tech?