> Its much harder to shoot down a space GPU farm than a terrestrial one.

Not by as much as you may hope. Getting a rocket up to altitude is much, much easier than getting one to orbital speed:

https://what-if.xkcd.com/58/

Hitting satellites in orbit is still hard, but ASAT was demonstrated (albeit the target was designed for the test) by the USSR no later than 1968, and on a more arbitrary (end of life) satellite by the USA no later than 1985: https://en.wikipedia.org/wiki/Anti-satellite_weapon#List_of_...

The severity of one single missile depends on the orbital configuration; I'm expecting everyone to declare "we have adjusted our strategic priorities elsewhere" (i.e. "this was a bad idea") well before there's a relevant quantity of them.

Given how cheap laser welding has become, I also foresee ground-to-orbit lasers being credible. They still need quite a large aperture and corrective optics, but that's had known solutions for a while now thanks to astronomy.

> And its closer to space assets which might want it for targeting during times of war.

Not so far as I can see. If you want really low-latency you have edge compute on the weapon systems themselves; otherwise you use the existing satellite comms (e.g. Starlink) to just talk to something hardened outside weapons range.