Having to case a guitar to keep it from losing its color in a very short period of normal use is a bit silly.
Casing a guitar isn't silly at all. It's the best way to take care of a guitar, and it's so damn simple to do. The fact that they don't fade is merely a bonus/side effect.
I started keeping mine cased after reading one of Bob Taylor's articles about caring for wooden instruments. Bob says they're pretty, but they're not made to be decor, and to case them to take care of them. He knows his stuff. And he's right.
The case keeps dust and grime (including airborne oils that are in houses from cooking, settle on the guitar, and combine with the dust to create goo) out of the pots and parts.
It buffers the guitar from temperature and humidity changes that occur all day, every day, in every climate, during a 24 hour period. In States like mine, where there are big swings in indoor humidity between seasons (2/3 or more of the year with forced air heating), that's even more important.
Wood is hygroscopic, meaning it both absorbs and releases moisture. When the guitar's environment is dry, the wood releases moisture and shrinks. When it's humid, the wood absorbs moisture and swells. It's the shrinking and swelling of the wood that creates the need for neck adjustments and annual setups, and it also creates the finish crackling one sees on nitro guitars (mine are all nitro). In acoustic instruments, it can also create cracks in the wood itself. I had that happen in the past to an expensive Martin back when I kept it out.
Depending on the floor the room is on, the humidity is higher the closer to the ceiling (basements), or drier (main floor).
I keep a humidipak in each case. It keeps the humidity inside the case at a constant 45-50%, whether it's humid or dry (the pack releases moisture, but also absorbs excess moisture). A case is necessary for them to work at all. No need to run a humidifier in the room in winter, either.
As a result of all this, none of my guitars, including the guitars that have been here for 7-10 years, has needed so much as a tweak on the truss rod, let alone a setup - since I got them! I used to have to have my guitars set up at least yearly when I kept them out. No poky fret ends, either.
Now I pull them out of a case for a session and they are 100% ready to go. Plus they feel great.
Casing a guitar can't hurt it. Hanging it can.
So I think it's foolish to
not case them, that is, if you buy them to play instead of to serve as wall decor. Several of mine go for five-figure money. That's a big investment! And my Core models weren't cheap, either.
Symphony players case their instruments, because they represent a big investment. It's simply the best way of doing things. Anything else is a compromise. And it's so EASY to put a guitar in a case!
WTF people? It takes how many seconds to open a case and pull a guitar out, or put it back? Not many!
Yes, when you go somewhere, the cases are heavy. So stick the guitar in a gig bag for the time you'll be away and travel light. Modern gig bags won't solve the humidity problem, but they work well for everything else a case does.
