I won't quit my job, at a moment If I can work on both then it would be useless to quit my job, as doing both is giving me opportunity to earn extra income, So I would prefer to continue with both.
I too, when I am done studying and already working, I would prefer to do both, work while after work I will find bitcoin as an extra, I can't really go fulltime here because my course is not computer related and my studies would be useless if I won't work on a day job....
If you have a good full time job then you should continue with it, as you need only few hours to work on bitcoins, that you can manage any time during day or night time.