On Mac and Windows, I have to think twice about whatever applications I install because, as you said, any application could royally screw with the system.
On iOS I can download effectively whatever I like from the App Store without worrying about it screwing up my system. That peace of mind is worth a lot of money, and is why people pay a premium to be in this walled garden.
I have no desire for for my iPhone to have the same threats presented to my Mac or PC. I also have no desire for my Mac or PC to be as locked down as my iPhone. There is room in the market for both. Trying to legislatively eliminate this option is ridiculous. If you don't like the device's security policy, then don't buy it.
If iOS allowed sideloading, you could just stay in the app store though. Problem solved.
As a developer, I just want to be able to distribute my apps to myself, my family and my friends without having to pay $100 per year and without having to ask Apple's permission for us all to do whatever we want with our $1,000 phones.
Our government will sort this out eventually now that iPhones have over 60% of the active phones in the US and that number will not be shrinking since 90% of the youth market is on an iPhone.
Apple will be forced to open up sooner or later, just like when "Ma Bell" used to force you to rent a phone from them just to use the landline that you also leased from them - once they had a majority market share, they got broken up. Same thing with Microsoft bundling IE with Windows - they were forced to share their APIs with third party companies. Consumers and small developers don't decide this. Lots of small, medium and large businesses are affected by Apples restrictions and they'll keep fighting it for us.
The problem with the 'don't buy it' argument is that Apple spearheads the 'what can you get away with' movement. Most companies follow Apple and customers bear the brunt. Examples are headphone jack removal, non-removable battery etc.
On iOS I can download effectively whatever I like from the App Store without worrying about it screwing up my system. That peace of mind is worth a lot of money, and is why people pay a premium to be in this walled garden.
I have no desire for for my iPhone to have the same threats presented to my Mac or PC. I also have no desire for my Mac or PC to be as locked down as my iPhone. There is room in the market for both. Trying to legislatively eliminate this option is ridiculous. If you don't like the device's security policy, then don't buy it.