Publishing an app for fun, experience, and no profit

The lure of passive income is well documented but for many developers the costs outweigh the benefits.  Once you charge money for a web or mobile app, a responsibility to customers is formed - you have to fix bugs, keep backend services highly available, stand up a customer service process, etc.

I like tinkering in mobile apps but don't want that pressure.  I created an app to scratch an itch.  It's not great but it works.  It was published a couple years ago when not many apps with comparable functionality existed and has built up a group of steady users.  I recognize many Android apps are undesirable but put mine one level above that category (the UI is not pretty).

So why should developers self-publish apps that don't make any money?

• It's fun!
  
  This is my primary reason.  Don't you like seeing your software being used?  My users' data gets stored remotely so the more rows I see added, the more I know people are using it.  Also, I love getting emails from people who just say "thanks".
• Great technical experience
  
  I fancy myself as a full-stack engineer so this has been a great way to see something through from beginning to end.  I get to touch lots of different technologies - client code, security layers, database endpoints, etc.
• Do something different
  
  I don't cook up mobile apps in my day job.  At least now I can talk reasonably intelligently about Android, AWS, and Google App Engine.

• Get the first one out of the way
  
  Maybe one day I'll want to build something independently for profit.  Ever get the feeling you don't know what you don't know?  I feel like this experience will help me avoid that problem, at least partially.