Classic Traveller Book 2 envisioned interplanetary craft able to move under constant 1g to 6g thrust, moving from planet from planet by accelerating continuously to midpoint and then decelerating constantly from there until arrival. Makes for a nice quick trip, but even something like an Earth-to-Moon jaunt at 1g meant peak velocities of 60,000 meters per second - and it gets a LOT worse for those flights out to the local gas giants. At those speeds, accidentally smacking your ship into a stray orbiting pebble is like getting hit by a tank round. Worse, perhaps: if I understand the physics right, the pebble becomes a high-temperature plasma under that kind of impact (as does a bit of your hull), interacting with your hull rather like a small shaped charge. By comparison, the M1 tank's cannon hits muzzle velocities of a bit under 1600 meters per second.
I'm guessing the developers might have had that in mind when deciding spacecraft hulls were as strong as they say. I'm not sure even these hulls would survive some of the potential impact speeds, but it's a game, not reality, so I'm content with the approximation.
As far as I can see, there's nothing wrong with the thin-hulled stuff doing orbital work or coasting slowly from planet to planet. After all, our Voyager series did just fine without needing 2cm or 33cm steel walls.