Sorry but do you understand technology at all ?
iTunes Music Store is a web service. Whether it delivers HTML or XML to a thick client is irrelevant. It still needs to deliver a tremendous volume of them in addition to managing the downloads. And by and large it has worked tremendously well.
iTools/.Mac etc are all the same thing just rebranding. Ping was a product failure not a technological one. And GameCenter/iMessage use iCloud so not sure why you listed them.