It's odd to say this about a guy in a cult, but perhaps he's a lot smarter (at least professionally) than most of us give him credit for, since he very rarely makes movies that aren't good. Go through other A-list actors and you can pick out a few or several movies that were big disappointments. For example, Will Smith has Wild, Wild West and After Earth. Arnold Schwarzenegger has Last Action Hero, Batman & Robin and Sabotage. Both of those guys can win you over with their personalities, so it can't just be Cruise's likability that makes all of his films good. Perhaps he picks his roles a little more carefully than other action stars, works with only directors and producers that he trusts and, maybe, takes a larger behind-the-scenes role in producing, himself.
It's not like everything that he's touched has turned to gold (maybe silver, though), but nearly everything of his has been as good as or better than expected. The upcoming The Mummy movie would seem to have all of the ingredients for being a bomb: it's perceived as a remake a very popular movie, it's too soon for it and it seems to play a hokey premise rather straight (unlike the other one)... yet, somehow, we're all going to be surprised that it's better than we expected, I imagine, since that's Tom Cruise for you.