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.
iTools/.Mac/MobileMe/iCloud are all the same thing, but signify the number of reboots they have had over the years. Each time they say "it's fixed!" and then yea, it's not.
Be my guest if you want to believe Apple is great at the web. Meanwhile Google will be feasting.
Hater be hatin', but what have you done that handled 65 billion multi-megabyte downloads, securely? And we haven't even talked about movies yet.