Light-HawkBurstarFPS in space isn't the issue (and it's while in atmo that it would become the problem ftr). The issue is as Saka has basically said: it has essentially been deemed too much effort for insufficient return by the FDev management. All the bs the CM's throw our way is to avoid admitting this.
And yet Braben said back in the kickstarter days that ships were already being modeled with their interiors in mind and mentioned some gameplay mechanics in mind for how to make use of them.
Also if I'm remembering correctly, I think someone in the Odyssey alpha test phase, managed to glitch themselves inside of the hull of their ship and found there were incomplete models for the ship's interiors already present. They were no where near complete but they were there. I could be wrong. I'll see if I can find it again.
That's my point. They were all pie in the skied lets put it all in there, really knock their socks off. Then 'something' happened. What was that something? FDev management looked at the time it was taking and deemed it too much effort for insufficient return.