Not OP, but how often do you have an app that is exactly how you want it? You might just shrug off the small annoyances, but you could fix them and make the app something that becomes second nature. The UI won't suddenly change, so you won't have to relearn how to use the app, just like you don't have to relearn physical interfaces.

The above are all reasons I use emacs.

for REAL. when I started using Emacs, everyone told me Emacs was old and I should use Sublime Text II or Atom. Now they all tell me Emacs is old and I should use VS Code. I wonder what they'll tell me to use instead of Emacs in ten years :)

This is (largely) why I do all my coding work in an editor of my own creation. It suits me perfectly, and it never changes unless I want it to.

It is only very rarely exactly how I want it. Often, I cannot even find software that is half of how I want it (and is sometimes difficult to change). So, sometimes I will write them by myself to work differently. But, other times another program can be modified as needed, but that is less common, to me.

I've used some horrendous software in the past and it's nice that - even though I can't fix that software - I can write my own software and make it behave exactly how I want it to.