If you didn't like Mission Breakout, would you still feel it's an awesome park? Because for me, Hollywood Land is now bad, Paradise Pier is now bad, and half of Grizzly Peak is now not as good as it once was. The only things I personally really enjoy at DCA are Radiator Springs Racers, the area surrounding Grizzly River Run, and Buena Vista Street. That's it, though.
I view DCA's roster this way. There are six E-Tickets: Tower of Terror, Soarin' Over California, California Screamin', Toy Story Midway Mania, Radiator Springs Racers, and Grizzly River Run. Now of these six, only two are Disney quality, those two being Tower of Terror and Radiator Springs Racers. The other four are all very basic (Screamin' is a bare bones coaster, Soarin' is a movie, GRR is a rapids ride, and TSMM is a video game) and removing them wouldn't do huge damage to the park so long as their replacement was ok. For example, while Soarin' Around the World isn't as good as Soarin' over California, it's not terrible. So long as Tower of Terror and Radiator Springs Racers exist, changing up Screamin', Soarin', TSMM, or GRR isn't going to be a big deal. Now Incredicoaster is terrible but if Tower of Terror was still around, it wouldn't be a big deal because you still have Tower of Terror and RSR plus the other three. But now you don't have Tower of Terror, just Radiator Springs Racers because Mission Breakout is also terrible. So now we have an inferior version of Soarin', an ugly overlay of Screamin', a bad replacement for Tower of Terror, two basic rides, and a really good attraction in Radiator Springs Racers. That's simply not enough to really hold the park for me.