It isn't cost effective to build good software... for a few users. I develop some internal systems. They are very complex and each of them have 40 users at most. The ROI of Apple polishing every tiny bit of a software is great. If each of their 100000 users spend one second less, it is a ROI of more than one day. Human beings are very intelligent. They can learn to play a musical instrument, drive a car, operate a machine and to use shitty software.
Does the public domain books that you "buy" and cost 0,00 also count as a sale?
You helped to define the way I think. Thanks and good luck.