We, as players, like to min/max our designs. But we don't have to live on the damn things for months on end. One of the reasons that the Navy has changed their acommodations is that they HAD to, in order to keep attracting the right kind of person to serve. Barracks housing is pretty decent these days, in some ways its just like living in an apartment. When you are a volunteer there's really only so much shit you'll put up with till you decide the military life ain't for you.
And, of course, technology has really enable a lot of changes. Things are smaller, so you have more room for more shit - including crew comforts. Plus you need fewer crew with more automation and machinery. But, the flip side to all that is your crew ARE smarter, and educated, so they are less willing to put up with crappier conditions when they know better (or have better options to avoid).
There are exceptions, of course. Cramming a bunch of guys into a ship for an assault is one thing. But living that way day in and day out for weeks or months is another. Nobody wants to live in an assault shuttle, but you can bet your troops wanna ride one down if someone is shooting. They'll temporarily trade survivability for creature comforts.
