Ever since I put the camera inside the 787 cabin, I've liked the side views a lot more.
I think that the airliners in the game should have an internal Cabin view. If cabin modeling (seats, overhead bins etc.) is a concern, then we could have the current system where camera views are restricted, but to showcase the wall and window only.
As for those who prefer external wing/engine views, we could have a button to toggle that preference; whether it's in the views button panel or in the aerofly settings.