I never worked in a bookstore, though I spent quite a bit of time in them. (I was mistaken for an employee more than once.)
The ones in my area were mostly chain rather than indie, but in any case, romance was always well represented. And in grocery stores (which often had little book sections back in the day), the selection was always a few bestsellers, with the rest of the space being all romances. Of course, back that far, there were no ebooks or self-publishing, so the whole dynamic was different. Readers who want there to be a paperback even if they aren't going to buy it may be unconsciously influenced by the old days, when book meant paper.
But for some reason, the phenomenon isn't unique to older buyers. A little while after one of my colleagues outed me to my students as an author, one of them saw a paperback copy of my first book. "It's real," she said in a surprised tone, though she had earlier told me she'd seen the ebook listing on Amazon. Somehow, ebooks weren't real books in her mind. Go figure!