One possible answer: the Federal Circuit remanded the case back to district court for further proceedings, and there would be another chance for appeal after those proceedings completed. SCOTUS may have decided to kick the can down the road. From what I understand, this is not uncommon; complex cases sometimes offer multiple opportunities for appeal, and higher courts will sometimes decide to say "no" to the earlier opportunities even if they eventually say "yes" to one of the later ones. Sometimes, higher courts like to let things play out more fully at the lower levels, since it allows the record and arguments to further develop, and so they feel they have a better foundation to base their own decision on. (Plus, with a huge workload, there is something to be said for delaying taking on something big as long as you can.)

(IANAL, this is just the best guess of a layperson.)