I'm not emotionally attached to it; it's more a lazy thing.

It's easier to draw a way rather than an area (because it's easier to stop along the way when I see something), and it's easier to add closed ways to an existing multipolygon than to create a new multipolygon each time. (And easier to create "holes" in advance if I know which multipolygon they will be added to.)

Maybe I should clean them up a bit at some point.