did you see Rogue One? They covered that. Galen Ersa designed the reactor/exhaust point as a single point of failure so that the death star could be destroyed. The entire movie relied on that point and getting that info to Leia and the rebelionI'm just waiting for the movie on how they designed the Death Star with an exhaust port of doom, and then the sequel, in which they forgo the exhaust port in favor of a larger channel big enough for the Millenium Falcon. Perhaps they could be called Derp Star, Parts 1 and 2?