Moriarty, Spiderman against Green Goblin, James Bond against Ernst Blofeld--the list goes on. But villainy in real life is far more often perpetrated by idiots.
I tend to forget this. I've complained about the villain who feeds minions to his sharks when they displease him. Why would I go to work for the guy in the monocle who kills off his minions? That's moronic.
Fargo. This movie is hilarious. William Macy plays a feckless loser who hires two criminals to kidnap his wife. The criminals are hilariously stupid as you can see in their various interactions. Their madcap antics turn this comedy into darkest black when they start murdering innocents.
This illustrates something significant. You may need to be smart and/or good to make it through life, but you can be both stupid and evil to create a great deal of mayhem. The best crime writers know this and they can make the reader laugh at the stupidity of enterprising criminals who end up re-enacting Wile E. Coyote pratfalls and Darwin Awards. This can add some comic relief to some rather heavy reading. And then you can make your readers feel guilty for laughing.
Let's face it, you don't have to be Darth Vader to choke the life out of your girlfriend. And you don't need to be Gabbar Singh to toy with the victims of your cruelty.
I think stupid villainy is something like Mr. McGregor's veggie garden. You've got a nice, tidy little garden going on. Then some pestilent little bunnies come along and take what they want and cause damage much greater than whatever value they could derive.
These criminals may aspire for the "big score," but they are seldom capable of more than venal enterprises. Their misdemeanors reflect the lack of trust they inspire. Smart people do not leave high-value items unprotected. They do not entrust high-value items to lame brains. The protection afforded high-value items is seldom penetrated by numb-skulls. The criminal who is a dunce must settle the scrap-metal value of a cast-iron antique he steals because he lacks the sense to take it to somewhere besides a junk-yard. They feel they've put something over on you when they lie about matters inconsequential.
Much Ado About Nothing. He has the role of constable, he's not very bright, and he tells himself he's not a criminal by affecting the intelligence he does not possess.
Of course, the cretinous villain does not realize his disability. He thinks he's the smartest guy in the room. This makes him ripe for manipulation. Which I suppose is something the super-villain with a monocle knows. S/he can promise the dimwit shiny things. "After we hold the moon for ransom, you'll be right there at my side."
More likely, the smart villain can set up the blockhead villain with a "big score" to the end of getting him caught, whereupon the smart villain can steal the lolly from the evidence room. (This scenario does not even require a super-genius villain.)
So, next time you're up for some crime writing, or want to put together a mystery, consider putting some addle-brained imbeciles on the chessboard.