Defense systems in space need to be... in space.
I don't think people are looking at this the right way. They need to be inaccessible to terrestrial and air weapons, have lower latency, not be dependent on power plants, etc.
Far easier for someone like Iran or China or the US to take out an LEO satellite than an underground data centre, or even a surface on in the case of DCs in US or China.
That's true, but they're also very vulnerable to ground based LASERs.