Besides that nowadays to get a good income must have some good project or very lucky to invest high and be able to get an amount fixed of bitcoin, soo no makes no sense get full into bitcoin as we can use it as an extra source.
Earning thru bitcoin isn't a full time job unless you own a huge site related to bitcoin like gambling site or an exchange with tons of users that you earn about $50+ a day.
If not then you're income may not suffice for your daily needs.
even with a huge site, the owner never spends all day behind computer checking things out.
the bigger the business the more support team you need and you as the owner will only stay away and just take your profit and check things out once in a while, so you can easily go and have another day job.
that may be true but then there are far better things to do than having a 9-5 day job. like staying with your family which is very important thus reason why you want to earn actually. if you are married, you'll find it hard to find time to spend with your family while having a 9-5 day job.