The only thing horror about Resident Evil has always been the lack of Ammo and the decisions you have to make to survive. Other than that the games have never been scary at all. Not being able to see around the corner made you scared to go around it because Zombie could be right there. That element was removed from 4 and was never present in Silent Hill anywhere.

RE is a different type of scary than Silent Hill and it has to do with gameplay and not story or atmosphere.