Oda is good at making good characters but he can not succeed every time: with Oden he tried too much and his MC after decades is both the one that supports the whole manga and a concentrate of plot power, sometimes contradictions like with the sudden "secret dream" bullshit or having Ace die because he was too cocky but Luffy can try everything everytime and he will always win... So maybe Luffy is the worst, not appreciable, character.