If you seriously think TW does nothing AOSP can't do then perhaps it's seriously been that long since you've eaten or drank anything. I will make a donation to Sumaritan's Purse on your bahalf.
For one, you cannot get Yahoo! Mail/Contacts/Calendar pushed to a Stock Android device without a third party application or forwarding (which requires Mail Plus in the US). TouchWiz can do that. AOSP cannot. You cannot get WLM or Y! Messenger pushed to your device on Stock Android without a third party application (and they certainly don't integrate into Contacts the way Social Hub IM does), yet TouchWiz can do that. Apart from synching rudimentary contact data (and Google+/Talk crap) the stock android contacts app is utterly provisioned off from your social networks and other profiles. TW does much better there than Google could ever dream to, it seems.
I'm not sure what you use your phone to do, but I use it to get real stuff done. I like to be productive. When you send/recieve over 5600 SMS a month on top of all the FB/Twitter/eMail communications you're getting you want something that's a bit more integrated than Google's fragmented-as-all-hell stock Android user experience.
No one I know uses Google+ or GTalk. I need something better. TW > Stock. Stock is useless to me, and many people agree else JB penetration would be incredible as they'd all be buying Nexus devices...
Stock Android is the least socially-connected OS on the market. Thanks but no thanks to the mile-long/wide share menus in my apps/gallery, and terrible battery life since I'm loading my phone up with tons of services to make up for deficiencies in the base OS service connections/support compared to TouchWiz. TouchWiz hasn't relaly been bloated since TW3.0, for the most part. You must be thinking about HTC Sense...
Stock just seems terrible to me, and quite useless for the way I like to do things. This is about the buggy ICS update and going back to GB, which I have already done on my phone (got AT&T to flash it back to 2.3.6), not about your fetish with a barebones OS image that many people here could care less about. I'm sure there is a forum or thread to tell people what they need to learn and what they should do with their devices, though.
Y'all need to just root my god how can you stand stock at all aosp is the way to go
I think if you checked (as in: been aware of it, since I don't expect or want you to change anything) your attitude you'd be less surprised at the tone of the responses you recieve.