He gave the American people Barack Obama, and for that he deserves our indifference, if not our scorn.
I'll blame McCain for many things but never that. Reagan himself couldn't have won in 2008 after Dubya tarnished the GOP brand as thoroughly as he did.
This being said, McCain could not have ran a more lackluster and uninspired campaign, the objective of which was seemingly not to defeat his Democratic opponent, but to defeat his pick for Vice President.
He certainly deserves prayers and sympathy as a human being, but we should always remember him for exactly what he is ... a corrupt U.S. Senator and a failed presidential candidate.