At risk of saying something wild, most people like to like good people. Heroes aren't named that without doing a little bit of heroics, and making us root for them because we know they'll do the right thing - even if that sort of becomes rooting for ourselves as we control them.
That said, we all also love a flawed character. It's easy to love an anti-hero who struggles with knowing what is right, but who (generally) manages to do so despite these struggles.
And - even when these struggles are really, really dumb - they make some of the most engrossing parts of any game or story we come across. Even though some of these characters have colossal blunders, they only enhance the plot, as they provide further complications and barriers to be navigated.
Be they villain, hero, or something in between, seeing a character simply totally drop the ball by making some misjudgment can be the highlight of a game - as it at the least will make you feel a little bit better about getting lost with where to go for like ten minutes beforehand.
10. Groose - Legend Of Zelda: Skyward Sword
For all his many, many flaws, you can argue that Groose meant well, since he did plan on saving the world as the Hero of Hyrule - just, unfortunately, that happens to not be him, but Link, which makes his mistreatment of Link at the start of the game a glaring error.
Because Groose is straight up a bully to you at the start of the game, and coincidentally almost convinced that Zelda has a thing for "the Groosenator" and not your fine yellow headed self.
Mercifully, he goes through some pretty big character development, and eventually becomes both not a huge jerk, and one of your most trustworthy allies.
However, this doesn't change the fact that, had he not been an ass to you for like five minutes, he might have had this character development at the start of the damn game. As it is, he sucks for a good while - and has some hugely wrong presumptions - until he gets his act together.