well the answer is simple, this particular vessel exists in a solar system in the near future where commercial ventures in space are far more common than scientific. This is more representative of the eagerly anticipated future of making space travel affordable for many more people than today, maybe it seems out of context given Orbiters default, sparsely populated solar system... and i think there are plenty of people who could see how a paying passenger cabin could be "functional".
Of course though We try and make it as flexible as possible, as any aircraft manufacturer might... we were not able to do everything with the mk1 that we wanted and only a page or two ago we were talking about different interiors and how thats been planned from the start, and even how it could possibly be user editable.
If this hasn't been implemented yet and perhaps may never be, well i do apologise, but i hope no one has the impression that we owe the community one type of vehicle or other... neither of us ask for money - I dont know about Doug I've had just one donation in the 3 years i've been working on the model and that guy had no complaints, so i'm basically happy satisfying my own curiosity and making my own model first, as long as Doug has no strong objections. and between us we do try and make everyone happy, but we only have so much time to devote to this project... not meaning to complain or anything, no ones forcing us to make stuff for orbiter, but thats just how it is. and if its not useful to you, well no ones forcing you to fly it.
At the end of the day though can do everything with it that you could do with the dg, xr1, xr2mk1, and more... so its plenty functional.
some of its up to you guys also of course, there's more features, more room, more panels and doors and whatever else we can throw in, and you'll no doubt have more room to be creative with your own ravenstar this time around... given the planned features if you read the thread, I see no reason why it can't be outfitted for everything from your exploration mission to slyly shooting down someones satellite or even more imaginative things.... thats why you already have editable cargo for example and payload bay at all.