That's what my seller told me, when I suggested that both bathrooms needed toilet seats.
"Nobody wants to sit on someone else's toilet seats."
In my entire career, which now spans millenia, this is the first listing I've ever had, where the seller has removed the toilet seats, and refuses to replace them. So the bathrooms look a little forlorn. The house is vacant, and freshly cleaned, so it's not as though it's dirty, or disgusting.... they're merely missing. I imagine, it's true, that most new buyers will replace the toilet seats. But c'mon.
Personally, I think it's odd, but her philosophy is that it won't stop someone from making an offer, and if the buyer insists on new toilet seats, we can provide them.
By "We", I'm pretty sure she means me. ;-(