However, if "not getting grabbed three times" is a skill that is integral to success in competitive play, than it can be argued that it is a prerequisite for a certain level of ability.
Let's say that there's a player who regularly beats every character but Ice Climbers, and when he has to play a competent Ice Climbers, he loses every time, because "he's not good at not getting grabbed three times." If Ice Climbers are a popular character in the metagame (say, there are a handful of good ones that regularly go to the same tournaments), then how well the player can do against anyone else doesn't matter a whole lot, since that glaring weakness just means that virtually anyone could develop a pocket IC's and wreck the guy.
If it's really that easy to beat someone, then that player is either playing a deeply-flawed character (you be the judge), Ice Climbers are too good (trust me, they're not; they don't do so well in a fair amount of matchups), or the player is severely lacking in a skill that is necessary to succeed, which means he is not a very good player in that metagame. Either way, something needs to be fixed, and only the player can do that. "Skill" is subjective and doesn't necessarily have much to do with how good they are at winning.
It's sort of like if I started maining Ganondorf and started losing to people below my skill level because of it. You can say, "He's so good--If only he didn't play such a ****ty character," but I'm still not good in the current metagame if I don't fix my bad habit (in this case, it's using a ****ty character). If I were to hold on to Ganon and claim "I'm so much better than you! If only I didn't have this cripping handicap that I'm not willing to come to terms with or fix," then, who cares, since I'm not winning matches? That mentality would make me as bad as any scrub, really.