It is like the confirmation prompts that banks requires you to approve before you can proceed with the the transaction. Even when we have logged in using our own account, they tries to save us from our own follies by asking for confirmation again.
In the same way, windows has now become so integral for general computer users, they cannot tolerate it to go bad in any way. People are becoming increasingly hostile to the situations where Windows will not work and they will not listen to any argument as to why it did not work.
So, UAC prompts seems to be a way out. One wish they could be less obstructive, but there is no way making these less obstructive than these are currently now. Only thing that can be done is to improve the message that comes in the dialogs box. We will have to live with it to be warned in the rare cases where our own foolishness may stump us.