It's not that bad if you're really confident to trade Bitcoin. However, despite of the time and effort you spend, there are moments you can't really take profit consistently since bearish season is for accumulation. Therefore you have to wait for an increase in order to trade your Bitcoin. Just shows that there's a certain time on when you can profit and a time to fill your bags. That being said it's not really wise to quit your job to be a full time Bitcoin trader, though no one can stop you if you think that's more beneficial in your situation.
Anyway, we have different opinion regarding this. Maybe some prefer to go full time because it's convenient rather than working 8 hours a day on a day job while some don't agree. But just remember to always choose what's giving you a profit that can sustain the needs of your family and it can be both if possible.
Its ideal to trade (preferably invest for long term) in Bitcoin along with your job or business rather quitting it altogether. I may take weeks or years for Bitcoin to see its next bull run and this can be a nightmare for anyone depending solely on it. Bitcoin in Dec 2017 was trading on its ATH of 17k and in next Dec it was trading on 3500$. There are many things we can do along with job to increase our income like participating in signature campaign here etc. Job or business is must if you have a family to feed.