Not all. Just some. Doctor Doom makes perfect sense to me. He's driven by three motivations: To rule the Earth. To rescue his dead mother from the bowels of hell. To destroy the accursed Richards. You've gotta respect a guy whose supervillainy can be so succinctly boiled down into a three-point "to do" list.
Lex Luthor makes sense to me too. Depending on which era you're readin', he's either got a mad-on for Superman because of his lost hair or his lost superiority over Metropolis. Lex likes being Number One, whether it's as a ruthless businessman, President of the United States, or evil science genius. And he uses his brilliance and keen science know-how to make himself bajillions of big Luthor bucks that he no doubt rolls around in naked every afternoon in between board meetings. You have to respect a man whose policy it is to use his super-intellect to make himself filthy stinkin' rich. (Not so much his Superman-killing policy.)
Which brings me to the definitely-lower level of science villain who's smart and savvy enough to create technology powerful enough to at least temporarily go up against Spider-Man or Superman or Batman or the Flash, but doesn't cash in on it: what's his story, I always wonder? Why has the megalomania gotten in the way of him seeing that he just developed a dandy radioactive-powered ice gun for which world conglomerates would pay millions to lease or buy the technology, and instead decide to use it to rob the Second National Bank of Keystone City? You know, I'm a tiny little stuffed bull who sometimes has trouble reaching the Lucky Charms on the top shelf: I'd gladly pay for a handy home version of extending stilt legs to get at the cookie jar. Let's not even think about the military applications of an army of Stilt-Men. (Actually, let's do: soldiers striding fearlessly across harsh terrain on giant metal extending stilts: cool!) So why use that creative genius to become a second-rate supervillain instead of a world-class rich guy, awash in caviar, Ferarris, and all the leggy supermodels you can wrap your arms around?
Let's take Daredevil villain Death's-Head, for example. This creepy creepster
All panels in this post are from Daredevil #56, September 1969
Now you may be asking, "Bully! What possible real-world consumer application could a transparent horse have? Sure, it might be humorous to see them race at Aqueduct, but aside from the entertainment value...?" And that's where you're wrong, true believer! As DD later explains:
"Treated so its flesh was transparent and only the bones could be seen." Now, let's leave aside how blind, radar-dependent DD can tell how something is transparent (really, Matt, to you there should be no difference between a white porcelain horse and a clear glass one) and instead focus on the genius of the idea: Death's-Head has created a process through which flesh, muscle, and organs can be rended invisible so the skeletal structure inside can be seen. Improbable, maybe, but hey, we're talking about the Marvel Universe so I'll give that a pass. (The only thing higher than the levels of radioactivity and magic in the Marvel Universe are the suspensions of disbelief.) What's utterly improbable is that Death's-Head is using the genius serum to perform a cut-rate Scooby Doo routine to scare Karen and Ma Page off the old homestead instead of cashing in on the millions to be made using the process as a medical breakthrough. He woulda gotta away with it too, if it wasn't for those meddling Page kids and their pesky Devil!
Just think about it: Need to see if a bone is broken or cracked or mishapen? No need for an x-ray; just brush on Miracle Fluid X and take a big steamin' gawk straight at it. You could probably use it for pre-natal examination of a baby, or checking for head trauma, or determining right at the emergency scene if a limb is broken. Modern medicine would pay millions for such a procedure! Again, there's got to be some military application as well: it's near-invisibility, and with some black-ops tweaking could possibly put Sue Storm out of business and make it a heckuva lot easier for Marvel artists to draw the adventures of Nick Fury. Why, what could possibly go wrong with such a medical breakthrough? There are no drawbacks, no shortcomings, no possible or conceivable arguments against using such a process on humans...
Okay, super-villainy it is, then!