Actually, both RE and RE0 are million sellers.
Also, remember when Mikami "jokingly" said he would be fired if Viewtiful Joe didn't sell well? Well it's sold well in Japan, and we'll see about the US, but maybe he wasn't joking after all...just maybe.
Also remember that it's unusual for people in Japan to leave companies they have worked for for a long time. Yokoi only left Nintendo because of the shameful failer of the Virtual Boy, and Mikami hasn't shamed himself as far as I know. While people in American and Europe leave companies all the time, it's very unsual in Japan, especially when youa re talking about the big boys like Mikami.