To answer the original topic, for me right now ship design absolutely is its own mini hobby. Since I moved a few years back I haven't had a regular gaming group so most of what I do is just for my own amusement. Of late I've been tinkering with ideas for ship design both for my amusement, but also as inspiration for 3D modelling.
Reading back over the thread I thought Epicenter raised some very valid points. Ironically, I've heard some of the same from friends in the FX industry regarding concepts for space ships for TV and movies. Some of them have gone to the point of talking more to people at NASA and Navy personnel to get a better understanding of how things are done and why in the real world and how that might translate into space. But I don't think necessarily all of Epicenter's points would or should be applied universally. Military ships should have lots of bulkheads, compartmentalization, etc. Same for scout ships and research vessels. But merchant vessels, passenger liners and pleasure craft (yachts) might have considerably less, and in the real world they often do (sometimes with disastrous results, but people don't want the inconvenience of all those doors and hatches even it if eventually gets them killed, human nature). So some things on his list might be conditional depending on the type of vessel (or maybe that luxury liner or yacht does have bulkheads but they're more expensive because they have to be both larger and not visible as what they are while still being able to slam shut automatically in an emergency, that might be an interesting ship's option). I also think some of what he mentions could easily be included in existing ship design, but its just not noted either in the design rules or deck plans. How much storage is there really? Does a ship's corridor look like something off the ST:NG Enterprise or more like this:
With storage space everywhere, spread out all over the ship in various compartments. In the past people didn't give it much thought, back in the 70s, 80s and 90s we didn't
know to give it much thought but with the changing times, being able to see live streams from the ISS, our awareness has changed and these question become more relevant. Not just in gaming but in movies and TV and written fiction, people want what seems realistic and the bar for that has been considerably raised.
Anyway, to answer the OP, yeah at this point ship design is kind of the main part of the hobby for me now. I've always enjoyed tinkering with ship designs and I'd like to think I've gotten a lil bit more realistic with them over the years but there's always something you didn't think of. Maybe at some point I should share some of what I've come up with.