Well, especially such people who own a lot of Bitcoins or make a lot of Bitcoins care about the price. Because your loss is higher when Bitcoin price decline when you have 100 Bitcoins instead of 1 Bitcoin. I know what I am talking about 
So I do not think that it is possible for everyone at the moment.
every thing is possible in this world but some task are difficult to achieve and some are easy, although it is possible to earn a living with bitcoin, but to me it will not be a wise decision to depend of bitcoin for living, because some time the price of bitcoin fell down so much and it become difficult to trade in bitcoin therefore we should always consider bitcoin as a secondary option.
People who earn a lot of bitcoin on a daily basis does not care for the price drop or anything else happens with bitcoin, because they already earned enough bitcoins and stored them in their wallet and they also earn more as much as they earn everyday and they just use some of them for daily use and store others and the price always grows again.
So far, I have found it to supplement what I get. It is not big by any means, but the speculation and holding can be exciting. Waiting for the fork and the later or sooner
halvening will be another thing.
Yeah it is possible to earn a living with Bitcoin but for that to happen you will have to earn allot of Bitcoin. halvening will be another thing.
So I do not think that it is possible for everyone at the moment.
People who earn a lot of bitcoin on a daily basis does not care for the price drop or anything else happens with bitcoin, because they already earned enough bitcoins and stored them in their wallet and they also earn more as much as they earn everyday and they just use some of them for daily use and store others and the price always grows again.