In catching up to my Hulk history I FINALLY took it upon myself to red Defenders comics and start from the start with Marvel Feature 01-03, I can name a few villains from these stories (I'm up to issue 18 of volume 1 of Defenders) that came up with some boneheaded ideas.
Everyone in the Marvel Feature Series:
*Issue 01: Evil doctor is dying, decided to build a giant computer using both science and magic to destroy the world, and brag to Doc Strange about it on his deathbed.
*Issue 02: Evil alien that can turn to cloud hypnotizes two astronauts to start their own children TV show with terrible writing to allure children to ride a rocket to a new planet instead of the destroyed home planet of Xemnu to repopulate a new planet for himself by letting human children reproduce and destroying Earth.
*Issue 03: Evil crazy occultists want to summon Dormammu (Door Mouse Guy) to top the entire planet crust with scorching hot lava and be his loyal minions, even though he was insulting them even before commencing with their plan and talking down to them.
And then the regular series starts, and Steve Engleharts issues are at least proper in villain motivation for 11 issues, then came Len Wein with some solid issues and two stories of villains with absurdly nutty plans:
*Xemnu wants to repeat his mistake from Marvel Feature 02, but with population of an isolated town instead of children this time and a rocket built slowly inside the Town Hall. He also defeats Hulk and attracts the attention of other Defenders who again put a halt on his crap plan.
*The Squadron Sinister want to destroy the planet Earth by selling it to an alien aquatic archaeologist to allow him to melt the icecaps and cause global flooding, all because baby mind Hyperion is mad that he was locked in a container and before that his atom world was demolished, the subatomic world that existed within confines of regular Earth.
*Wrecking Crew destroy buildings more pricey than the ransom they demand, cherry-pick buildings owned by Kyle Richmond (the newly joined Defender at the time; Nighthawk) and ask for millions of dollars and cause more property damage, not caring that their money will lose value the more property they destroy (even if you were to remind me property destruction happens all too often in superhero comics, 80s and 90s comics had it especially worse). The Four Stooges do that more often it seems based on their appearance in Ultimate Spider-Man cartoon, not caring that they will eventually attract attention of superheroes in a city boatloaded with them who defeated them more than once before.
*SIGH*
List any ideas and stories you can think of that you read in the pages of some Marvel Comics. Max, Icon and Malibu count as well considering they are Marvel Imprints.