I certainly understand why that's the default (like the sliding doors on vans). Just saying that anyone who wants to use a hitch mounted bike rack will find it to be a real PITA to deal with, assuming you want to have the rack, and the swingout, and still be able to open the rear hatch with only a modest amount of hassle.
We have a different bike rack that folds down, but the vertical portion is still too tall to allow the swingout to open when it's folded down.
The sightlines issue is modest, but something that happens a lot more than stopping on a busy road and opening the rear hatch. When you turn around and look over your right shoulder out the rear window, you're looking mostly at the tire on the passenger sid.
FWIW, in Japan where 4Runners (Hilux Surfs) have factory mounted rear spares, they're on the driver's side, not the passenger side.
Just some food for thought, I'm very happy with my bumper, it's just that if I'd thought of this before we had them built, I'd be even happier.