spaceship spinal guns are just the sci-fi version of insisting the A-10 is actually good and the design compromises on every other aspect of it is worth having a big gun
"Yeah, we're going to make the main structure that runs the whole length of the ship hollow, and exert huge forces on it, don't worry about it."
"Yeah sure, you have to point the entire ship at the target, and that both severely limits our ability to perform manoeuvres and makes our field of fire easy to evade, but we only really need one hit so it'll work out."
It makes sense as like an orbital bomber platform though, something moved in once you have control of high orbit of a planet to just blow the fuck out of things on the surface since you don't need to do a lot of aiming and it should have an escort
