If a guitar is dull, dead looking, plain, as lackluster, it is also know as uninspiring, that could make the guitar not want to be picked up and played. If you go to a guitar shop that has had a new delivery of guitars, leave it a few weeks then go back again, and generally speaking you will find all the uninspiring guitars left on the shelf.
"How it looks" is a subjective question all on its own, as people's preferences in "what looks good" are undoubtedly different, just as "what sounds good" has different answers for different people. For me, a little bling is all right, but it can quickly become 'excessive bling' to me. Plain doesn't necessarily = boring to me if I like the way the wood looks (especially mahogany, which can appear stunning to me in the right conditions, more so than rosewood). But someone else may prefer rosewood to mahogany, or prefer flamed maple over anything else. Which is fine.
Made by CRYSTALL!ZED by Bri, LLC. Their Marketplace site says the binged-out guitars start at $1k USD. "Have your acoustic or electric guitar CRYSTALL!ZED with 100% genuine Swarovski crystals! I can do any instrument in any color or design you choose. Guitar shown is a custom built Taylor Guitar covered in over 4000 flatbacks in Crystal AB. Message me to discuss your custom project! ALL ARE MADE TO ORDER USING YOUR OWN INSTRUMENT!"
So you have the expense of the guitar in the first place, then at least another $1,000 USD in crystals, depending on what you want them to do. I also, suspect, like Derick, that this doesn't help an acoustic guitar's sound. I can't see the top vibrating as it should under the weight of all those crystals glued on it.