Building another business while accumulating your Bitcoin is not a bad idea, and is very much possible, let's all stop seeing Bitcoin as a source of income because it may cause panic when ever there's a dip or fall in Bitcoin.
Economist will always advice against having only one source of income but if you are just starting to build your financial status, it's better you start with what you are more comfortable with. Some people choose Bitcoin because they have a better understanding about it and some choose to open a business first. Which ever ways, i don't think there's anyone that's not profitable as long as you have a knowledge about it. But after you have made enough money from your first start, you can invest in other things.
Actually it is not really advisable for an individual to have a single source of income because sometimes you may fall down on your face. but if you have many source of income if one failed you, you will have other source to rely on Without feeling too disappointed. You cannot rely on only bitcoin because it can raise higher or lower anytime, you also have to invest in some business.