I used to believe that, until I started poking around in VR. I think this actually was the case until SRVs were introduced. The SRV bay just doesn't fit properly on ships like the Sidewinder and Viper. For example, the bay used to come up through the floor on the Sidewinder, until they finally fixed it by pushing it down, but last I checked (maybe Odyssey fixed this?) the bay protruded awkwardly through the bottom of the Sidewinder, not at all a good fit.
IIRC, many small ships had a different (and arguably better) design before SRVs were shoved into every one of them. I will grant you that the effect of this will be minimal on a ship like the Anaconda, but that ship has it's own issues, like hallways designed for cats rather than average-height humans.
And yes, I've seen the fan art for the Sidewinder interior, and it's epic. I'm really impressed with what that artist pulled off, and it does show Frontier could do it, but that art doesn't scale with the reality I've seen in the game itself. I'd be curious what concessions the artist had to make, like did he have to shrink the SRV or the bay? Also, does that ship the extra module slots added, or was it made before then?
Speaking of module slots, I can't wait to see the sentient mainframe that is the size 7 limpet controller