Missing perverted.
That's hands down the worst.

Dumb protagonist is good and I like him.

I lost count of how many mangas I dropped because protagonist was too dumb or dense, it just get old eventually so it is fine if it is this way for a little while but they better be making progress rather than staying dense forever... Violent is also pretty bad, but really depends on context

for me violent , i hate physically/verbally abusive characters the most
i can tolerate dense mc as long he have some redeeming qualities

I ended up with arrogant because there have been way too many of them in the last few years, to make it worse they get arrogant after getting power freely given to them.

But like others have said, you missed perverted, I would have voted that one too for sure.

maybe genki

I don't think it should count as a trait; of course there's a chance I don't even have the correct semantics
because I find a character with spectrum stuff/anxieties very enjoyable

having a debilitating illness is like a Nicholas Sparks script
oh no my TB truck kun cough cough

All can be interesting if they're properly addressed in the story and treated as flaws. Also "cute" should not be a character trait but unfortunately I suppose it is.

What I hate the most is arrogancy. It mostly has a negative tendency than being proud, and usually leads to defeat and other stupidities.. It's also the root of egoistic character, in my opinion. And most arrogant protagonists that I found are usually taking for granted all the privillege they have (power, money, etc). Kinda irks me.

I dislike egotistic protagonists. There have been protagonists I've quite liked despite having any of the other traits - even proud ones who I have something of a soft spot for. But I can't stand people who are too full of themselves. Super unattractive.

Merry Christmas all!

As someone stated, a perverted protagonist is probably the worst. I know it entirely ruined my possible enjoyment of High School DxD, because Issei is literally that bad. And there was a manga that I shall not name where the main character, being perverted, even rapes a girl... and the story tries to justify that. The story kept trying to justify several evil acts. It wasn't a hentai, it was just sickening and the author deplorable for putting out such a work.

Now, there are protagonists that are decent that are slightly perverted, but at that point their main trait would be something else more positive like optimistic. We are talking about main traits, right?

That said, due to the sheer amount of dense/dumb protagonists, I voted for that. There's only a handful of the worst protagonists, but there are so many dense/dumb protagonists they hold arguably half the entire manga/anime industry and have been choking out otherwise decent stories for decades.

As a lot of you think the dense/dumb MC is way to overuse, and gets boring pretty quickly, that is why a voted it. I get that a perverted protagonist could be the worst but i don't get why everyone goes to the sexual deviant, instead of the twisted mind kind of perverted, i like my protagonist to feel more real and a little of sexual desire makes a lot of difference.

Missing so many of the actual worst ones:

Pathetic
Doormat
Coward
Super-nervous
Crybaby
Wimp

All the ones listed in the poll are pretty much nothing.