Why did people cheered for hogan at wrestlemania?

WHY DID PEOPLE BOOED THE ROCK IN WRESTLEMANIA, I WOULDN'T CHEER HOGAN OVER THE ROCK, THE ROCK LEFT WWE BECAUSE HE WANTED TO BE AN ACTOR BUT HOGAN LEFT THE WWE TO COMPETE IN OTHER SHOWS, WCW AND NOW TNA, AND HE DOESN'T ELECTRIFY LIKE THE ROCK.