The intention/purpose of the limit on fluids was to prevent people from assembling liquid explosives inside the plane. The contents of your bladder would not help with that.
It's an attack that never happened and wouldn't. It's nuts.
They should have banned underwear because the underwear bomber /did/ happen. But sure, that's awkward and would impact revenue, (I don't wanna go nude so I won't fly unless I have to), so the ridiculousness of doing so triumphed where it did not with water and shoes.
Lock on the cockpit door was worthwhile (unless the threat is a psychotic German copilot, worked bad then). Also the successful terrorist strategy had expired useless even before the end of its first use on 9/11 as passengers found out, realised new rules: fight back now, hard.
Bastards at Heathrow stole a sealed jar of Fortnum & Mason jam from me. For security! Because onion jam could blow up a plane. FFS. But sure, you could buy the same stuff once through security and take it on the plane at inflated prices. Where there was a financial incentive to do so and a secial interest to lobby for it, the idiocy stopped. In 5 meters.
The purpose of these moronic rules was /not/ what you think it was. It was just a sequence of moronic compromises around dumb ideas influenced by special interest. You can't respect it and respect your own intelligence. Security is actually important, do better.