Just want to add my $.02
It all depends on what kind of system you have - after reading the comments, I can see why most wouldnt want to remove their system every night.
I have a lace system with a poly rim. I use Walker tapes on the rim. I remove every single night (I tried NOT removing it when I first got it over a year ago, but sleeping with the system on, and waking up with massive bedhead sucked!). By the end of the day, its not that difficult to peel off. I can imagine for those who have full lace systems and use bonding adhesive, this would be different. I wouldn't want to remove it every day in that case. However, I am glad I went the route I did because it FEELS SO GOOD to let my scalp breathe, to itch it, every day I run the electric razor over it so I dont have stubble to get irritated. I should add that I was not completely bald, so I still have lots of hair growth under the system. And Im a hairy guy, lol, so it grows FAST.
I bought a hairpiece stand on amazon for like $11, and put it on the stand every night. I will put the walker tapes on top of each other until I get 3-4, then they are real easy to peel off the poly. No residue, no mess, my system lasts longer (Ive had it a year 4-January, and my trusty hair salon says its in good shape still. I never shower with it on, and God no, I would not get it wet or wash it every day! Thats nuts. Its going to wear much faster. I wash it 1x every week, sometimes 1x every 2 weeks if Im not real active (like in the winter), every 2-3 days I use spray in conditioner for hair systems and style it. I dont usually have to restyle it every day because I dont sleep with it. Most mornings, I am good just brushing it, or spray-in conditioning and brushing it. With the conditioner, I never need hair spray or gel, the conditioner holds it all day long.
Your mileage may vary, but I wanted to share what works for me with my Poly rimmed Lace system.