According to The Monster Show by David J. Skaal the monster movie industry used the horror genre to showcase intense fears related to wars (foreign and domestic) such as WWI and WWII, the atomic bomb, Red Scare, Cuban Missile Crisis, Vietnam, HIV AIDS, birth control, etc. all under a veil of make-believe.
The 50s horror movie spoke to the complete devastation witnessed on their TV screens – the atomic mushroom cloud. The idea that nuclear attack was imminent created fear of the world we could expect after the cloud dissipated – genetic mutation – increasing our fears literally to an insurmountable size (ie. Godzilla, The Attack of the 50 Foot Woman, The Blob, Attack of the Giant Leeches).
Additionally, fear had increased around the idea of outsiders invading, whether they were extra-terrestrial or Communists. Correspondingly, the horror genre reflected back with Invasion of the Body Snatchers and Invaders from Mars. The true terror of Invasion of the Body Snatchers is the idea that your neighbor, close friend, boss, wife, husband, and children could be infiltrated by this [Communist] conspiracy. No one was safe from the invasion. You couldn’t run or hide from it like other monsters because this monster dons a human face. (Additional invasion/otherness films include Plan 9 from Outer Space, The Day the Earth Stood Still, and Killers from Space.)
In the 50s we begin to see a tongue-in-cheek approach to violence, death, and horror. Vampira (and her awful jokes) pervaded local access channels showing monster movies from an earlier era dealing with the same fears of war. Her ridiculously cheesy commentary had a laissez-faire sentiment toward death and appealed to audiences who were terrified that any day could be the last if they heard the air raid siren. In essence, Americans were so terrified of being blown-up, they decided to joke about the inevitability of death, treating it as escape rather than something to fear.
In terms of cheese-specific horror movies we have Abbot and Costello Meet the Mummy and Macabre. (Macabre isn’t so much cheesy as surrounded by cheesy gimmicks. The theatres gave people certificates for $1000 life insurance policy as they entered the film just in case the movie scared you to death. Some theatres also had ushers dressed as doctors and surgeons, staging ambulances at the entrances.) Other cheese-riffic 50s horror winners are The Thing that Couldn’t Die, The Giant Claw, I Was a Teenage Werewolf, and The Brain from Planet Arous. Though these films were not intentionally amusing, it’s difficult to believe that audiences found them frightening.
Revenge as a motif in horror films did not enter the scene until the late 60s and early 70s when films started to reflect uprisings against an unsympathetic government. As if echoing the origins of Elizabethan tragedy we begin to see the proletariat rise up against people in power, and in so doing discovering their own innate power. We see this most explicitly in the movie Carrie.