Earning a living with bitcoin has got higher possibility. The reason is that bitcoin gives low earning but several methods of earning method is available. If the user involve in most of the earning method then sufficient amount for an living can be earned.
I m 100% agree with your answer. because if you want to choose the bitcoins for your regular earning so you have a big responsibility.
If you use bitcoin's earning for a part time job, so it will be better.
I think it depends on someone if what he is comfortable with, whether he can manage to use bitcoin as his only income, or he wants to make it a part time income.
There are a lot of people who are earning a living with just bitcoin, like the ones who are running gambling sites, exchanges or many other websites that earns them commission, so for such people it is really not so hard to earn a living with it.
And also there are a lot of people who take it as a part time income so they do trading, signature campaigns or many other similar things.