Even in seemingly open country, coyotes can appear almost out of nowhere, and come from directions you don't expect. When they do, you often need to make a quick shot, usually on a moving yote. If you're not at lowest power (which IMO should be 3 or 4 max) you don't have a large enough field of view, so you're trying to shoot at a furry blur bouncing in and out of view.
On the other hand, longer shots (400+) usually involve a coyote that just won't come in to the call. They stand around or even sit or lay down just out of range (or so they think). There's often enough time to range, dial, and take a shot.