The chainsaw in "Texas Chainsaw Massacre"  is written by Kim Henkel to equate eating meat with oral rape.
Consumption of meat extends as a rape of the victim, man or animal, when the murder itself is an unwanted objectification and violation of a conscious life for the pleasure of a "higher" lifeform.
The cannibal family serve the most dangerous authoritarians through incest, necrophilia, criminal capitalism, devil magic and general psychotic behavior.
They are still victims and creations of a system that reflects them. They are merely the bottom of the totem pole, who go unnoticed and unmasked. They are castrated by society and strike back with this phallic anti-social extremist consumption. They are a consumptive of betrayed, abandoned, vengeful, crazed, isolated, corrupted and completely alien monsters in our own realist view of society then... and now.