It sounds like they found the room design pretty but not useful. Optimization problem.

I came expecting - or rather hoping against expectation - more about the design of soups. I like your analogy. And to build on it, I will give an example of a simple soup that just works (at least it gets served for 25 years):

• dice 1kg carrots (less than 1cm^3) stew shortly with 
• 2 tablespoons of olive oil and some water.
• dice 1kg potatoes,
• optional: slice and dice one leek bulb,
• one spoon of finely cut parsley (can be from a shaker),
• two tablespoon vegetable stock, and cook with
• enough water that everything can still easily move around when stirred. Cook until al dente.
• Add either: 300g meatballs (readymade or from ground meat with one teaspoon of salt and pepper)
• or: add more spicey vegetables, e.g., diced celery, add pepper, or something else.

Serve with soup noodles and offer additional flavoring for people who like it spicier.
 

Note: I am not sure about the units tablespoon and teaspoon; adjust relatively until it tastes.

Related: Key lime pie and the methods of rationality explain across three levels of meta using cooking as the running example. And to another article [LW · GW] using a cooking example. Here we have the third one, which proves that all advanced rationality techniques can be explained by cooking.
   

This includes a rectangular, shiny plastic floor mat, which they placed over the ornate, fine red carpet with the aim of "stopping the carpet from wearing out". They added a pile of cardboard, which now blocks an mahogany bookshelf's carved wooden branches. And a bulbous plastic printer now sits on what was a uncluttered pine table top, with paper boxes splayed around it.

I think this suggests that maintaining your design wasn't practical for them. They need to put their cardboard and printer somewhere (and good luck buying an aesthetic printer). Perhaps the concern about the carpet is silly, but if it really will wear out in a short while then protecting it and maintaining some of the aesthetic value is better than not protecting it and having to buy a replacement before they've actually gotten value out of it.

If you could have re-arranged the room by adding space for their cardboard boxes and printer and protecting them from having to buy a new carpet, then yes they messed up. But if your solution is to get rid of the cardboard boxes and printer and to buy a new carpet in a few years, then your design isn't appropriate for them.

To compare to Gunnar_Zarncke's soup recipe, I wouldn't recommend a meatball soup to a vegetarian, but if I can recommend a soup that can either use meatballs or spicey vegetables, then that's a good recommendation for everyone.

I thought this was interesting. Recently I've been sort of obsessed with design, particularly audio design. Unless you get lucky, or are a savant, it's impossible to just make good things. At least for me. Until I learn the "theory", and have some experience in creating rather than just consuming, I don't seem to really know what I like