This is no surprise, as this is the approach Disney takes with just about every building that guests don't enter/exit from the outside. The UoE building will be the "face" of the GotG ride. They decided to keep the exterior of the building intact because they like the way it looks and believe it fits the vibe of this ride. Most guests will just assume that the building they walk into is the one that houses the ride. The gravity building exists only for logistical reasons. From Disney's perspective, in an ideal world, guests would not know the gravity building even exists, hence the "go-away" color scheme. This is the same approach taken for rides like Soarin and RnRC, among others.