I can think of a few organisations that benefit financially, a great amount from the fact that cookies allow them to track users. Ad companies like Google and Microsoft spring to mind. The same organisations building our major browsers... Conflict of interest? You better believe it.
Imagine if browsers reported a user-resettable uuid sent over on each connection open. Advertisers get the benefit of being able to track users, do it more securely since no data is ever stored on the client, and must eat the cost of actually storing the key-value pairs, instead of passing it down to users and expending massive amounts of bandwidth bouncing the data back and forth.
It's not about killing cookies, it's about finding a better solution that solves the problem better.
Note: I work for a startup that "benefits financially" from tracking users—a feature without which we would not have a business.
This already exists in spirit, in the form of "Incognito" or "Private" browsing. This doesn't solve the protocol issues of cookie bandwidth and insecure storage, but it does provide a user-resettable store of cookies.
