I'm not convinced by the official line
The El Reg line that is. If the mission requirements were for a satellite platform for quick testing of arbitrary instrument packages a basic disposable system designed to sit under a fairing would have been faster and cheaper to design and indeed to operate. Not to mention that it would have drawn a lot less attention to itself. As for keeping the returning vehicle out of the hands of opposition that's a matter of giving the platform sufficient delta V capability. Wings aren't going to to help you much if you're on a ballistic course for central China. Alternatively a few kilograms of strategically placed high explosive should do the job.
No, in the end, a spaceplane has one USP- the ability to bring arbitrary objects safely to earth from orbit. Now I'm not saying the USAF are about to go pinching Chinese satellites any time soon but I don't doubt that they would liketo have the capability to do so. And that scares me quite a bit, to be honest.