Do they want the vinyl itself or do they want the cover art and so forth?
- They want the cover art
- They want a physical token representing an artist they like
- They want to financially support the artist in a direct way
- They speculate they might get a player someday (much akin to book buyers leaving books on their shelves unread for years on end)
1 of the above might be the primary driver for any given buyer but I'd assume all of the above play some part in their motivations.
For my part, there's something visceral about owning a piece of "physical music", as it were, even if I never play it.
I also think people generally underestimate "potential playability" or aspirational record player ownership as factors in buying vinyl. A LOT of people who may never own a record player in their lifetime still think they might, & even if they don't their kids or grandkids might. Vinyl collections are heirlooms.