This munition is very rare, has to be aimed a very long time before it can hit anything and the whole process is very noticeable. I wouldn't lose any sleep about that.
Counterpoint: it would, reciprocally, take months to launch a military strike to disable a military asteroid base, so it offers robust second-strike capability. You can no longer launch a sneak attack on your enemy's strategic bases.
The short timescale of nuclear war decision-making is chaotic, destabilizing, and has almost led to *accidental* apocalypse several times in the 20th century. Slow, deliberated deterrence could take uncertainty and accident out of the equation.
