MI, Bourne, Bond and Mad Max were all new franchises once. People are concerned that MI won't last without Cruise but why should it? When someone is so tied to a series, to continue it without them is a futile proposition from the start. Hell, we've seen it play out with The Bourne Legacy. Better to create something new that can be built upon, except gather talented people to do it instead of doing a half-assed job. Bond is an exception here rather than the rule. And Mad Max is an even rarer case where the MVP of the franchise is the director rather than the star.