Picard seemed to have a zipper down the front of his uniform sometimes, but kirk used velco to keep his phaser attached to his belt.
Imagine this... There is gravity plating on most everything toilet related exacting weak gravamertric fields to attract body waste towards the best collections area in the toilet.
Hell, if they're going to manipulate universal forces (gravity) to control ones pee, why have a bowl? Just walk into a waste collection room, then whizz or plop in any direction which will be instantly caught by invisible holographic slides and shoots, and then labyrinthinely attracted to a septic tank somewhere before your bio-waste is recycled into bio-matter for the replicator.
I have this 20 year old memory of going into a public restroom, a few walls worth of urinals just going on and on... It must have been a movie theatre, but there was this kid, who had to have been at least 5 and raised by apes, because he was standing up, while his trousers and underwear were pulled down to where his ankles were, as he was just doing his business.
He didn't know how to pee!
Flaps and flies are magnificent, and he was not taking advantage of this fantastic invention!
Oh, the humanity!
Edit.
I've long since assumed that personal replicators are toilets, which makes me wonder if you're allowed to poop and pee at the replimat too?
In the Future, they want you to shit where you eat.
The more you put into the replicator the more you get back.
What if Voyager's replicator rations are not based egalitarily but it's a matter of the more you put in, the more you are allowed to take out?
(You know where I'm going next.)
You know how it's safe to drink other peoples pee but dangerous to drink your own pee?
So unless the waste collected by your home replicator is shot off to a grand repository of deposits where it's shaken and not stirred, it's really kinda filthy to eat anything out of your own replicator if in all honesty it's just a large bucket of your own resequenced faeces...
Guests.
You have to have Guests keep you quarter's bio-matter tank full for you.
Health consciously, you can only poo in other peoples homes, but if the amount of poo in your own home on Voyager determines how many replicator rations it is that you deserve for the week, it all becomes a massive popularity contest about how to convince the most crew to use your replicator in your room for their toilet.
Lines must have been drawn as Crewmen chose sides or paired off.