Well, first of all I request clean, freshly washed blankets and bedspread, then It doesn't matter which one as long as it is missing the bacteria left from all the prior guests.
It’s not always something that the hotel guest would “do”. Sometimes, based on availability, a guest is assigned a room with two beds in it even if and when only one bed is needed. That’s happened with me at least half a dozen times over the years, as has happened on the trip I’m on right now. (By the way, my wife frowns upon and prohibits me from picking up random women and bedding them in my hotel room. If not for her protestations . . . Grrrrrrrr.)