My sister likes my pristine Kirby Tradition and said "I'd like one like that! Could you get me one in red?"
Everyone sees something different in a vacuum Alex.
Vacuums which might not be appealing to you, may be appealing to others. It could be nostalgia, completing a series, or in this case; the opportunity to acquire a mint, boxed, unused Kirby as a gift. Some collectors enjoy the hunt, or rarity and value. For others, appearance is everything. Or it's the restoration challenge...
None of us are acquiring another vacuum just to clean carpets, and vintage machines aren't renowned for being lightweight, compact, quiet and efficient. It's that other element, unique to each machine or collector, that forms the attraction. Just how 'interesting' does a vacuum cleaner get?
Besides, these are lighter than later Kirby TechDrive models, they retain a large proportion of shiny aluminium as opposed to newer plastics, take HEPA disposable bags, have a decent hose, and still out-perform many later models (see YouTube Kirby Enthusiast).
What's not to like?