Tsk tsk tsk, the second reason sounds so mean(now more KH fans call it an abomination). I can understand the "don't turn Mickey into a poster boy for your company" a little, looks like more of a corporate thing, they didn't want their star character to be heavily associated with another company.
I think I'm only calling it an abomination because it's a mind screw sometimes to wrap your head around. It's a GOOD mind screw, but it still effs you up in the head sometimes.
Now then, onto Mickey. If I had three hours of the game where I had to play as King Mickey, I would not care WHAT else happened in the game, I got to play as that one character that it seemed impossible to turn badass but Square succeeded in doing so.
Before Kingdom Hearts 2, Mickey was just a kids' character to me. He was awesome, because he's Mickey, but he was still just a kids' character. He couldn't really hold his own in a fight. Then along comes Kingdom Hearts 2. Sora, Donald, and Goofy are all collapsing in front of the train station in Twilight Town, and Mickey freaking drops down from the sky and goes all Yoda on the Dusks.
THEN after I'm freaking out when it looks like Goofy's actually freaking
died, Mickey's fist clenches and he's all, "They're gonna pay for this," and throws off his cloak and summons his golden Keyblade and runs off in the most epic badass Mickey Mouse scene I've ever seen.
So if I got to actually play as this mouse in a segment that has story significance for a few hours, I would be beyond happy. Mickey is KH's Auron, and Kingdom Hearts even HAS Auron!!