i will not quit earning with bitcoin for about next 2 years , except the bitcoin price going down until 2$ , maybe ill bought some and vacum for few years 
Well if Bitcoin price will go down to $2 these days that means really a bitcoin economic crisis and I can say that chances of getting it up will take to 5 years and up or maybe will stable with that range. Hope It won't happen lol.
If bitcoin even went much below $100 it would probably be doomed. Miners wont continue to mine for long if they were losing massive amounts of money. I think the biggest risk is bitcoin needs to remain profitable for the miners because without them we're screwed.