In all reality, it was logistically one of the best moves USH ever made, primarily due to one reason.
Potter.
DM, Springfield, Universal Plaza and to an extent, Supercharged, helped get more capcity into the parks in ways very unique for Universal. DM the best in this regard, learning from mistakes from Orlando; brought home of the best themed areas of the park, and that they even made sure it can handle large amounts of people at a time, with the addition of a second theater.
And that while I do love T2, you are dealing with a park that at the time (and even now to an extent) does not have the luxury of space. Along with the fact that things being sacred for especially Hollywood, is an unfortunate after-thought. Despicable Me came in at the right place at the right time, when USH was very much getting the park ready for Hogsmeade and FJ.