We shouldn’t be too quick to classify something as an unrelated side project without understanding its purpose.
One thing a lot of business people miss is how integrated all of our work is. “A website or app might just be an advanced form of marketing” is just one example. Your “side” work helps with lateral thinking and keeps you open to new solutions and ideas. It connects you to different people who might be able to provide unique value to your business. And it helps fend off burnout while still keeping you sharp.
When I am looking for collaborators, I look first for people who are always “working”. It’s no good working a 60+ hour week at the office if you immediately disengage the minute you walk out of the door. But leaders have to give credit for those side projects, otherwise they’ll not only burn people out, they’ll miss opportunities that could be the critical ingredients for success.