Yes, I think you're absolutely right... there's definitely more to it than just the attraction, because this complex is much more than just a massive coaster. Universal hasn't strongly opposed the attractions you mentioned because, with the exception of I-Drive 360, they're mostly one-off attractions and not full-blown entertainment/shopping/dining complexes.
We know that Universal is closing Wet-n-Wild at the end of next year, and rumors point to them developing the space into another CityWalk type venue, with hotels/shopping/dining. Looking even farther into the future, there's also the large plot of land on Universal Blvd. behind the convention center that's being auctioned off on Nov. 18th, so if Universal wants to buy any of that land, they could also expand into that area as well. This giant 700' tower with several attractions and a dining/shopping complex below it would be direct competition to those projects, as well as the current CityWalk, whether Universal wants to publicly admit it or not. They're going with the light pollution/traffic/do more study argument to try and shut it down, but it's very likely they have ulterior motives.