If Rock can beat Hogan then why isn't Cena allowed to beat Rock?

Well the Rock has been long anticipated coming back to WWE. People were built up to see him and so people cheer for him. It's also has to do with their storylines. Rock is from the Attitude Era going against Cena of the current era. People like the clash of personalities. When people think of wrestling they think of the attitude era, the Rock. And so people would enjoy seeing the Rock win over Cena. People that grew up watching wrestling during the attitude era think that today's PG Era is too wimpy and everyone knows that Cena is Vince McMahon's puppet.