What the Mouse wants, the Mouse gets. And nobody gets in the Mouse's way. Abrams got an offer from the Mouse he couldn't refuse. Nuthin' personal.
Given how some fans felt STID took a back burner to other Abrams projects (hence, waiting four years), imagine their uproar if he decides to at least produce STXII, and the project is delayed by the SW movie.
I doubt Paramount's pissed. Nonplussed at worst. I bet if they thought it would help, they may even begin promotions for STID with, "From the director who will bring you the next 'Star Wars' movie...."
Abrams going to SW is a little like Roy Williams leaving Kansas for North Carolina. How could KU alum begrudge him returning to his first love after all the success he had with KU? And it's not like things have been bad for KU since Williams left. I'll hold onto that as a metaphor for what just happened here.