I'm sure private horse trails exist but I'm talking about public land where horses do have the right of way. The right of way goes Horse-pedestrian-bike. Sometimes people will cede their right of way, as to not force other trail users into dangerous positions. Trail riders almost never do. Mule and horsepackers often will, just not usually the purely recreational riders. I'm not saying anyone is doing anything illegal, but at the same time we shouldn't let the law get in the way of morality. Well trained horses aren't skittish. Well trained dogs aren't reactive. Well trained animals are rarely the problem and it's not like I'm going to blame horses for their riders' lack of control.