On the list of things that are horribly wrong with McCain, old is by far not the worst.
The man has consistantly done more harm than good. If we voted him in, there is absolutely no telling what he would do. On the major issues, he seems to side with the left more than the right. These are reasons to not vote for McCain.
I've said it before and I'll say it again. Given the choice between McCain and Hillary, I'd pencil in Al Sharpton before I'd vote for either, and that's saying something. McCain is virtually worthless as a Republican.
What you are saying is simply not true by any logical standards, assuming issues and voting matters.
McCain's voting record is largely very good, and more conservative then most GOPers.