When I am King...
There will be no wallpaper.
Have you ever moved into a house or apartment with wallpaper in it? Inevitably, it's some horrid floral pattern, or pink abomination, or simply old and cracked. So it has to go.
Paint you can deal with; you just paint over it. It may be the worst color invented since lime Jello, but all you have to do is bear with it long enough to slap another coat or two on top until it stops screaming.
But wallpaper? You gotta take it down.
Now if they'd gotten it right, they would have come up with some simple mechanism to take it down. Velcro strips. Paperclips in the corners. Post-it strength sticky on the back. Zippers on the sides. A wick to set it alight. A fuse to detonate it.
Instead, they came up with a new molecule, just for wallpaper, one that guarantees that you will take your house down along with the paper.
Picture the inventors, sitting in a chemistry lab, with this memo in front of them:
Need simple adhesive for non-permanent attachment of temporary decorations
Only the scientists were newly arrived from nuclear labs in other countries, and had a hard time with the language. They translated the note thusly:
Need strongest adhesive in universe for structural bonding of space ship joints
They created a bond so tight that it's easier to just pry off the drywall than remove the paper.
And of course, there is the mess. The inventors had some extra time on their hands and went overboard creating an adhesive that is also the messiest compound in the universe (barring fresh-ground coffee; that stuff gets everywhere).
The first attack is to simply paint over it; it worked for the pink walls in the bedroom, why not for the baskets-o-fruit montage in the dining room? So you paint, and you paint, and you paint ... and then, just when you've squinted sufficiently and convinced yourself it looks good, your spouse comes in and helpfully chimes in, “What about the seams? And the peeling? And that big crack in the corner?”
So you put the paints away, and you wait for another free weekend, and you get out the scrapers. And the steam iron. And the trash cans. And you try to cover the floor and furniture. And you spend the next 48 hours in hell.
So in my kingdom, there will be no wallpaper. It won't be sold, and there will be severe penalties for putting it up; violators will have to take it down again.