yes you can make living with bitcoin. There are many professional bitcoin trader that trading in the market.
They left their job, to be a professional trader in bitcoin because bitcoin price was very high especially at december last year.
So that does only means they left job because of this? and to think you have mentioned last december so that means it is only for that season? Honestly there is no guarantee to when the prices will shoot up or down, but the reason you stated was not enough to support their idea of quitting job because it only means it was a reckless move they did.