The problem is not with Microsoft. The problem is with Norton and McAfee. They want Kernel access. this is what their software is built around. This is exactly what the UAC is designed to stop. Stop giving programs access to the Kernel and causing havoc. Yet Norton and McAfee want it cause their software is built that way and they dont want to change it.
Yet bitDefender, Avast, AVG, Eset among many, many more redid their products to work with the UAC and the technology at hand and they work well. It is Norton and McAfee who got their wish and anytime you have those installed you give hackers and virus makers full access to your OS.
UAC doesnt come into it when the virus is designed to get around something in the program that is setup to protect you which has kernel access. This is why the other anti-viruses on the market are far more useful than both Norton and McAfee. As they dont require this kernel access and leave your system wide open should a virus hit without the proper definitions.
Of course symantec and McAfee are going to blame Microsoft. They dont want to take the hit.
Ballmer: Microsoft helped security partners on Windows Vista ? The Register
As you can see i can find the exact opposite articles showing the fact that they did help. It was just Norton and McAfee who failed. But the truth is what i said above. I did a lot of research back in 2006 when this was about and that is what the findings were.