Earlier quoted context omitted.
If you rely on the Apple app store, you have a single point of failure and have to jump through whatever hoops Apple decides. Which rather calls into question just how "indie" you really are. BTW it is possible to sell Mac apps and not use the Mac app store (I do). But I sell for Windows as well.
Have you found the extra work to also sell on windows to have been justified by the sales on that platform?
It is hard to give a precise answer, because:
-I don't know how the sales exactly split between Windows and Mac (my licence covers both), but I have an idea from downloads.
-It is more work to develop cross platform.
-Cross platform development always results in some compromises.
But, on the whole, I am happy that I choose Windows + Mac, rather than just choosing one or the other.