So, the topic right now seems to be "pro-ban doesn't want to step up their game and learn a character that goes even with MK".
I don't need to learn any character, we are all born knowing how to use MK!
Plus my Kirby does way better than I would ever hope to do with another MK. He might be easy and I *might* pick him up for the lulz, but I'm not really gonna get serious with him, I love my mains' playstyles too much to split my attention on a 3rd character. Today I went to a small smashfest nearby, and before I got too tired to keep on playing, I noticed that Kirby and ZSS will always be my best choices, even if the MU discussions say MK is better for an MU (like Snake or MK himself... I **** with Kirby in contrast to how much I don't **** with MK).
In conclusion, a couple of pro-bans know how to handle the MK MU, and even other MUs, with their current mains. Maining MK won't hinder them, but they'll still fare better with their own mains. I'm one of these people: I've got no problem fighting MK, he's just another character to beat to me, same approach as to any other characters in my eyes, just jump in and **** intelligently.
Mindgames are the best, and when you mindgame an awesome killing move that even you think "Oh ****, that's so awesome", that's when you know you clicked with your character. :D