Also it's really weird that families are traveling along on starships starting with TNG, even if the ship is to be sent fighting a Borg cube (!) (As per DS9 pilot intro). I'm sure there's some reason it might make sense in-universe : The dubious "we're not a military ship despite having over two hundred torpedoes" thing and keeping up morale in the strenuous long term postings imposed by space exploration... But it's not even like it is ever used for plots anyway save for a couple of small bits and drama, at least in TNG so far.
It's not weird. It's actually one of TNG's flaws.
It's completely underused. You never see what the rest of the Enterprise is even like. It's assumed to just be Federation ship. But if it has lots of people living on it, even civilians, this presumes that it should also have shops and things. It's amazing that for a show that touts a large scale galaxy that its world feels so limited and small. Despite its size, you would think the Enterprise-D is nothing but the bridge, a few turbolifts, a few rooms, engineering, sickbay, holodeck, Ten Forward, and the transporter room. Quite a little for small for a ship of that size, eh? Now compare to DS9. It's just a small space station yet has a rich, deep world where federation interacts with civilian.
TNG essentially comes up with a premise of handling civilians in it, but can you name a single permanent civilian character besides Guinan? No you can't. You will notice as you continue watching and talking that TNG gets a ridiculous number of free passes by its more hardcore fans that they criticize other series for that TNG does in leaps and bounds. For instance, they criticize Voyager for not living up to its premise when TNG does the same. Not having regular civilian cast members despite being a ship large enough to have civilians on it is but one example. You must use your imagination. TNG commits a cardinal sin of telling but not showing.
You also forget that Enterprise in TNG also while being touted as an exploration vessel doesn't really explore much of unknown space. Not like the original TOS.
