I completely agree. It's sad that they aren't seen as being so similar to chickens. Mine will often lay in the same spot like the chickens, enjoy dust baths and the occasional flight from one side of their aviary to the next. They love hiding in the tall grass and rooting around in hay.
It's a joy to watch them do their thing. Mine tolerate human presence well, and I've taken to rearranging their "furniture" every month or so to combat boredom. They seem to love exploring new wooden "caves" and ramps, and are quick to pick out new favorite nesting spots.
Coturnix japonica has only been bred for eggs and meat since the early 20th century. We've had far longer to "work" on chickens, and you know how much more space and enrichment we give them (in private flocks, anyway). To my knowledge, you can't simply breed an animal to tolerate close confinement, let alone to thrive in it.