Fuudo is a player who excels with footsies. Slowly whittling the opponent down, to get them into position to gain momentum and destroy them. He's trying to play footsies with a character who probably has the worst tools for them in the game, and I'm even including Alex when I say this. It's all well and good that he can manage that, and cr.LK his way to victory against Zangief, but he is objectively climbing a steeper hill with that handicap than he would have if he played pretty much anyone else.
But obviously, he's sticking with Mika because he loves the corner pressure. He's not the dice roll kind of player, but backing them into the corner to do what Mika does best is why he plays her. The thing is, Karin and Cammy have similarly oppressive options in the corner, especially Karin if we want to talk about 50-50s.
I think Fuudo will be dropping her like everyone else eventually, even if he says he still likes her right now.