It depends if you can maintain still your lifestyle if you leave your job and focus more on bitcoin. I have known some who quit their job for bitcoin because of the same reason. If you are already well-versed with bitcoin and sure enough that you can earn enough to pay the bills and have more money to put food in the table then why not? There is no rule that you should stay in your job because it is more secured especially if you are earning lesser with it compared to earning bitcoin or altcoin.