MB already demonstrated it can compete with the big guys. TZ was no match - No match for what? Where do you come up with this stuff?
And no, your logic was that by opening a quality attraction (MB), it frees up the glut of people wanting to ride RSR, thus reducing its wait time. And if that's indeed true, then it should have been in Disney's best interests to build a brand new GOTG attraction to present another option of thrill ride for guests to go on, thus reducing wait times for the other attractions at the same time.
Look at it this way, with CS down for a while, DCA has maybe 4 big-ticket attractions (MB, RSR, TSMM, and Soarin'). They could have had 5, had they given GOTG a new build. You seem to be intent on proving that doing that would have somehow made the park...worse???