Re: App Store
"- there is no central store where people can go look for your apps"
You mean the Internet? Or one of the walled gardens where your app is buried under 400,000 others? A "central store" is not an advantage here.
"- users must have a PayPal account or go through all the pain of entering credit card details, their address, phone number etc..."
No more of a bind than creating a Play Store, Apple, or Steam account? I already mentioned Steam by the way.. that's the water-vapour based malware from the previous post. And what about people who don't want to create an account and for whom tapping in a card number is sufficient?
Some people do not want one-click wallet depletion thankyou.
"- there's no way to push out updates"
You're going to put all of that effort into a game and not build in a patching mechanism? Plenty of others do.
"I don't think it's any surprise that the Apple and Android AppStores have been so successful for developers and customers "
So has the PC.
"and I just don't get why MS hasn't followed suit"
Because there's no need for it, unless you're turning a PC into a locked-down games console, which Microsoft seem to be trying hard to do with Windows 8.