Yes, this is something he came up with, and he has used it repeatedly (he also refers to red states as wastelands).
There are many theories about what caused him to come up with this term, but the widely accepted one goes something like this:
Bob was bullied in high school by macho white jocks due to his (by his admission) bad attitude, his Mario fetish, and the bizarre attachment to all things Nintendo (even going so far as to call the console wars of the '90s his personal Vietnam.) When Bob graduated and became a movie reviewer, he convinced himself that reviewing capeshit was somehow an "intellectual" pursuit, and after watching one too many movies on nerds versus jocks and watching the nerds win, he became convinced that, as a nerd, he was somehow superior to the jocks who bullied him; the fact that they may have gone on to blue collar jobs (not intellectual jobs such as reviewing movies) only serves to reinforce this delusion.
As such, in a textbook example of the pot calling the kettle black, he views them as horrible, irredeemable, useless sacks of flesh; due to the bullies being white, he especially views all white-skinned blue collar workers as ghouls who deserve to starve out in the wilderness as their blue collar jobs are automated. He believes their jobs aren't really working class jobs, because they can be automated, but his "job" and similarly disposable ones, such as Starbucks baristas, are the "real" working class. In 2014, at the peak of Gamergate, he would expand his vocabulary to "mayonnaise ghoul" to insult the filthy gamers, all in the defense of
loathsome women and known whores who would never fuck him if their lives depended on it.
At this point in his life, Bob has convinced himself that a superior future where he is free of diabetes, where women like him, where blue collar jobs are automated, and where all the loathsome mayonnaise ghouls whom he hates are dead from starvation and Corona-Chan is right around the corner. If only those obsolete ghouls didn't have the right to vote and a certain orange man wasn't elected, robots would be growing wheat on the moon right now. To believe otherwise would require some serious introspection and confronting the fact that maybe he is the useless lump, not the mayonnaise ghouls.
That's the theory, anyway.
Edited for completion