1: Many (and I would believe most) D+ film purchases are not one person, but two or more buying the film to watch at home with friends or family. For example, me and two buddies each chipped in $10 for Black Widow premiere access. Cheaper for all of us than a movie ticket, and a more comfortable viewing experience.
2: Repeat business is well over half of what the average film earns? First off, repeat business is never a guarantee. The film has to be good in the first place for people to want to return. By that logic, Batman V Superman made $330m domestic because it's entire OW ($166m) audience saw the film, loved the film, and wanted to see it again. I think not.
3: Streaming falls off drastically after the first week because families are done purchasing? Based on what?!?! And how is that different than films dropping off drastically after OW? "Streaming numbers almost always disappear in under a couple weeks out" Same with the box office, there's a reason HSX normally doesn't care about BO after four weeks.