You don’t always need passion about the subject matter. I was not “passionate” about cron jobs but I needed some tooling, built Cronitor, and now I never have to work for somebody else, which is something I CAN get passionate about.
As I recently wrote in one of the latest newsletters (you'll find it on MicroFounder, called "keep going"):
"It can be easy to abandon your project as soon as you launch and don’t see instant results – be it visitors or paying customers – but I’ve been looking closely how microfounders build their startups for the last 3+ years and I’ve almost never seen a real overnight success."