It's all in the eye of the beholder
Some people are attracted to customization and some people are purists. My dad is into antique cars and he is an absolute purist. He abhors any sort of customization. He thinks if you're going to fix a car up, it should be exactly as it would have looked when it rolled off the assembly line. To him, it's okay to add accessories it didn't have to start with, but only if it was actually available on that model. To him, any car that has been customized in any way beyond what was available from the factory has been "ruined". Personally, I don't have a problem with customization, be it on a car, a vacuum cleaner, or whatever--as long as it is done well. It's keeping that item out of the landfill or junk yard. Household appliances like vacuum cleaners are such mundane things that they are easily ignored and few people appreciate them for their aesthetics. So why not personalize it and make a statement. I've seen pictures of a few vintage Electroluxes that have had their leatherette replaced with something of a little bolder pattern that imparts an almost steampunk look to their art deco lines. I don't have the expertise to do it, but I've often thought it would be cool to paint a metal Electrolux canister, especially a smooth-sided 1205, a glossy black, midnight blue, or even purple and then give it ghost flames. It would be outrageous and not to everyone's taste, but it could make a really cool display piece.
The closest I've actually come to customizing a vacuum cleaner was replacing the outer cloth bag on my Kirby G5 with one from an Ultimate G. I didn't like the way the Ultimate G's curved bag topper made the new bag hang so I put the G5's burgundy bag topper on it to give it a crisper look up top and bring out the flecks of burgundy in the bag's fabric. I was tempted to swap out the emptor boot as well but ended up leaving it since the newer style boot was a superior design and it was overall less work. Some might say it's 'bojack' or a frankenvac, but I don't care. It works well and I like it.