The $100/yr developer account fee is an anti-spam measure, not an actually significant revenue source.
Apple and Google App Stores combined currently generate almost $100 billion in revenue per year. This is the biggest and best revenue source available on the planet for smaller developers.
Easy end-user side loading, and third party app stores is a direct attack on this ecosystem and will damage the livelihoods of developers who will have no way to fight against massive increases in piracy that will result.
Windows developers seemed to be doing pretty well, even without an app store...
But I am pretty sure the vast majority of applications on the App Store in the $1-$10 range would simply not have been possible to monetize in the Windows XP era.
Remember shareware? What percent of people actually paid for that? You think the market was even 1% the size it is now? CompUSA’s best annual revenue was $2 billion and only a fraction of that was software, and only a fraction of a faction of that was anything but enterprise software and big studio games.
And the market for apps on phones was a fraction of 1% of what we have now from the App Stores.
I’m not saying Apple is wrong to make as much profit as they want. But to say any more than a 10% take at most (likely less) is a tax to have the ecosystem running can’t be true. Not with the $100 a year on top as well.