I’m inclined to think Naruto is the most divisive of that group, largely on the basis of the particularly offensive nickname given to it’s fandom back in the day
. I don’t think the term is used as frequently online as it was, but still a significant part of the anime community tends to regard the anime as generic & uninspired. But yet a number of people still list it as one of their favorites & the fact that it’s still ongoing shows it must have some appeal.
Sword Art Online is another series that seems to have a fanbase that adores it while many others consider it overhyped. I never finished Alicization, but understood it was supposed to be the finale. But now they’re making an alternate movie version of the first season.
I’d also like to point out that a number of anime can be divisive because of the MC’s personality and/or motivation inspires strong opinions. Examples: Light Yagami (Death Note), Shinji Akari (Evangelion), Natsuki Subaru (ReZero), Shiro Emiya (Fate Stay Night). And Eren Jaeger (Attack on Titan) seems to have become increasingly divisive as the final season airs . Finally, although not the MC, I’ve heard many people say that Zenitsu ruins Demon Slayer for them.