The thing about the holodecks is that you have to have the sensors and emitters mounted all around for it to be effective. So you must have an enclosed or mostly enclosed environment to use them effectively. So the holoship in Insurrection is just a natural extrapolation of that.
And don't even get me started on the episode where the transporter made people younger, *and they treated it as a bad thing!*
Well, Guinan didn't mind, but she takes almost everything in stride. Ro Laren was bothered because she had a really crappy childhood (being a Bajoran raised during the Cardassian occupation). Keiko O'Brien was upset because she was married with a toddler, and being physically twelve was messing both relationships up (plus is would make Miles look like a pedophile). Captain Picard was annoyed because no one would respect an experienced officer who looked like a child, though he did consider going back to Starfleet Academy for a few years and getting another degree. So most of them had pretty good reasons for thinking the de-aging to twelve was a bad thing.