The tax ensures that any app developer has costs to recover. It thus drives them to do so in ways that reduce quality. At the same time it pushes away the hobbyists who may have decided to develop non-monetized versions of an app at higher quality.
(look at kids apps as example)
As far as programmer hobbyists, one has to buy a computer, disk drives, pay for internet access, food, coffee, etc. Most hobbies and passions have non-trivial associated costs.
In other words, you have to think about that before you even release, and as a dev it doesn't really make sense to do a one-off and leave.
That’s a logic I never heard before.
(It’s a line item in corporate accounting. That’s it’s only justification. It can easily be abolished if there is any motivation to do so)
Price = commitment