Speaking for myself, the author's post resonated with me in two ways - both that it's hard to turn off the business side of the brain ("Could this side project be a startup? Should I build it this way just in case I decide to do that later?") but also that I find it hard to turn off the manager brain ("Is this really the right order to do things? Is this the most valuable thing I could be doing?"), too, other people in the thread are mentioning thinking about opportunity cost to be interfering with their ability to commit to side projects (and also to actually _enjoy_ doing them).
It's easy to switch for some of us because the last thing in the world we want is more work and a startup is a lot of work. When I'm making something for myself it never crosses my mind that I could commercialize my hobby project because I know that's the fastest way to ruin a hobby.
