I disagree regarding software upgrades.

On the one hand, it is true that unless you have customers, what you have is just a hobby, and you should refrain from stuff that distracts you from solving the core business problem.

On the other hand, certain things become a lot harder and a lot more complicated once you have users, because the stakes are higher. So there is value in making sure you're fully upgraded and patched up before you cross the Rubicon, so to speak.