It's used in areas where you might have roadside parking along a road, either parallel or angled. It has higher linear density than parallel and is easier/faster. Compared to forward angled parking it removes the "backing out into traffic you can't see because your rear pillars and the hausfrauenpanzer next to you have completely blocked view of the oncoming traffic" (so you go slow and figure any drivers coming down the road don't want to die today either). You safe the road by stopping to park, and have road visibility as you back in. Coming out you get better visibility because your upstream neighbors corner is further from the traffic and your eyeballs are also closer. An added bonus is that bicyclists have very little reason to ride in the zone of opening doors, compared to parallel parking.
Some places it is popular. Changing to it from forward angled makes people crabby.