jessep is right - you cannot have a large amount of cheap and high quality software.
Note that there are some very large difference between the software on iOS and Mac. On mobile system, the vast majority of apps are more akin to small consumables - like having a can of coke or a cup of coffee.
On the Mac, you have much more complex software, that can take years (and even decades) to develop. This software requires serious investment of resources and time. If the ecosystem cannot support it, it won't exist.
You're right that the iOS store is designed to encourage a lot of choice at low prices - that's what sells iPhones. This might be okay for consumables but a non-starter for professional software that exists on the Mac.
I 100% agree with everything you and jessep have said here.
I don't think Apple really cares if developers are happy, nor do I believe this is by accident that prices are being driven down in the Apple App Store or the Play Store.
I believe both Apple and Google are happy to see the number of apps go up and prices go down since this results in a large number of cheap complimentary products to the phones and tablets in the case of Play Store and App Store, as well as to Macs in the App Store.
It seems like they are taking this straight out of micro economics 101.
Price of complementary product A (apps in this case) go down leads to increased demand for product B (iPhone, Mac, Android Phone, etc... here).
This is totally unsustainable for developers and leads to the majority of developers in the App Store failing, and hence the opt-outs we see from developers on the Mac app store returning to the old way of selling from their website directly and other channels.
From the Mac perspective this seems to mean low quality apps and sell once no upgrade apps (games for example) stay in the App store and enterprise or high quality applications continue using the old model of sales.
I don't think that is ideal, but at least there is a way for developers to continue to sell their products and so high quality products will continue to be produced.
I'm much more concerned with the long term viability of the App & Play stores in regards to phones & tablets. As developers we have no real alternatives to sell our apps outside of the Google/Apple designated marketplace. So I have serious concerns about high quality applications continuing to be realized unless something changes as over time the up front cost and risk to create new software just continues to get worse.
If Apple could persuade Adobe to sell Photoshop for $0.99 it would be good for Mac adoption. Then once Adobe goes out of business, Apple could buy the Photoshop IP at a knock-down price, make it Mac-only, and give it away with the OS.
What if Adobe gave Photoshop away for free and charged for support/integration? That's really the defacto situation now... Photoshop has always been very widely pirated.
No, the de facto situation now is that Adobe makes a lot of money from sales of Photoshop and no money from support/integration.
I.e., nonwithstanding the piracy, Photoshop makes Adobe a lot of money, and all that money comes from sales, and none of it comes from support or integration.
That was part of my point - that's what I think their reasons are for the policy on the iOS app store, and the MAS policy is the way it is to stay in line with that. I agree that it's a terrible system, but that's my best guess as to Apple's reasoning.
A lot of cheap abundant software doesn't help Apple in the long run. More expensive sophisticated apps would create a more useful platform, especially if the only existed on iOS. The easy stuff is easy to port or rewrite for other platforms.
Note that there are some very large difference between the software on iOS and Mac. On mobile system, the vast majority of apps are more akin to small consumables - like having a can of coke or a cup of coffee.
On the Mac, you have much more complex software, that can take years (and even decades) to develop. This software requires serious investment of resources and time. If the ecosystem cannot support it, it won't exist.
You're right that the iOS store is designed to encourage a lot of choice at low prices - that's what sells iPhones. This might be okay for consumables but a non-starter for professional software that exists on the Mac.