i think it's good idea to full time on bitcoin, it's not diffirent with your real job, you can be progamer or open new startup, then you can withdraw your bitcoin and use the fiat. it's a normal nothing diffirent with your job.
i doubt that it is good to work full time on bitcoins because bitcoin price is impossible to predict so the income would be really fluctuating and you wouldnt be able to make good money
At a moment its not affordable to get full time on bitcoin as price is not too high and also its fluctuating so may be in future if price goes higher then we can think of getting full time into bitcoin.