My attitude is that you should never be a job slave and you should always try to escape from working for others as soon as possible and become more independent, even if it might be more stressful. If your passive income become greater than your job, okay, let's think about this, you probably spend 10 hours a day or more in your job and probably 4 hours on your side project(s). You should analyze the market, is your side project something that will work well in the near future? Is it something that can generate much more money if you quite job and spend 12 hours a day? Are there any side projects that you wanna create and keep with it?
You should analyze your situation, possibilities and demand on your side project. Only you can decide whether it worth or not.
But I want to give you some my favorite people as an example:
Blumaan - It was a side project done during a free time that turned into a very successful profitable business.
Chris Bumstead - You may know Chris Bumstead, a very successful young bodybuilder. Bodybuilding wasn't his side project but he is an example of dedication for me.
Dustin Bates - music was always a side project for me that he was doing during his free time when he was studying electrical engineering in Ohio State University, he even holds Doctorate. He founded rock band called Starset that is doing very well. Their song My Demons is a real hit that a lot of people know around the world.