There are anime villains who blow you away with their nuanced backstories and reasonable if regrettable choices - and then there are anime villains with stupid motivations.
Sometimes, this seems to be intentional on the creators' part - there's no way that Commander Red of Dragon Ball's desire to use the Dragon Balls to increase his height wasn't meant to be absurd. At other times, though, it seems like it's merely the result of bad writing. Akihiko Kayaba of Sword Art Online had a motivation that left many fans frustrated rather than enlightened.
Which of these villains' motives are the most ridiculous?
Naruto has a lot of villains, and while some villains have motives that are fully sympathetic, others are kind of ridiculous. While the fandom doesn't always agree on which is which, most people can agree that Mizuki's motives were flat out ridiculous - that is, if they can be bothered to remember that he exists.
Mizuki wanted power, which is something everyone wants and isn't particularly noteworthy. Trusting Orochimaru with the means of getting it was dumb as hell, but that's more method than motivation. Rather than looking at his power grab attempts, let's turn our attention to his motivation for being the world's worst friend.
Mizuki and Iruka Umino were classmates, and eventually became coworkers. Mizuki loathed Iruka with every fiber of his being. Why? Because after Iruka lost his parents in the Kyuubi attacks, Mizuki was furious that Iruka was getting sympathy from their classmates. Even though nothing terrible had happened to Mizuki, he wanted that attention for himself! To rectify the situation, he buddied up to Iruka and set about surreptiously trying to make his life miserable through everything from subtle negging to actively sabotaging his career.
There are actually two different versions of Broly, and the one that's actually considered canon doesn't possess such a ridiculous motivation. But just the Broly Triple Threat saga is no longer official Dragon Ball canon doesn't mean it doesn't exist out there in the anime-verse - it just means that the current Broly can't be held responsible for the first one's idiocy.
Broly absolutely despises Goku. Why? Because when both of them were babies, he was enraged by Goku's constant crying. Nobody loves listening to a crying baby, but the idea that another baby would not only remember this but hold onto resentment until they were both adults strains plausibility. Apparently this happened because Broly unconsciously associated the terrible things that happened in his childhood with Goku's wailing - which is fine logic for a little kid, but by adulthood, he really ought to have figured out that blaming Goku made no sense.
A lot of people think that the reason Maximillion Pegasus kidnapped Yugi's grandfather and Kaiba's little brother is that he was trying to acquire the technology necesssary to bring his late girlfriend Cecilia back to life. This might have been reasonable, but it's actually not true - it was a change made by the 4Kids dub. In the original series, all he was trying to do was create a hologram of Cecilia.
Not only is this not worth hurting anybody over, but Pegasus could have easily gotten the hologram made by simply asking Kaiba, one of his buisness partners, for early access to the technology. If Kaiba refused to do it for free, he could have paid him. But instead he just resorted to kidnapping for pretty much no reason, destroying any potential goodwill between himself and the person who could have helped him achieve his goal.
Leave it to filler villains to have some of the most absurd motivations out there. According to Mahjal, if a woman no longer sparkles with youthful beauty, she may as well not even be alive. Despite what he implies, his former girlfriend Karin hasn't passed away - she just got older. Mahjal is so obsessed with her former appearance that he not only can't appreciate her mature beauty, he also starts binding young women's souls to dolls that look like Karin used to. So not only is he a misogynist, but he's also taking innocent lives. Good job, Mahjal, you truly are an idiot.