I read through it too, and felt deeply insulted. Luckily, our barn has it's own trails, so we don't deal with bike riders, which means I've never dealt with bike riders either, but, agreeing with everyone else, some of their arguements were just plain silly.
'They teach horses to ignore gunshots and cannonballs, police horses also don't spook all the time. Sure they can be trained to be calmer around such events, it just takes work. Are the equestrians going to do what is required to not present a hazard to other trail users, or are they just going to take the lazy route?'
^Okay, mister tough biker, let's see you train a horse to be calm around gunshots and cannonballs, and i'll check in to see how you do. *rolls eyes*
'oh come on. If there is one thing that is simple about this discussion, that should be a no-brainer, it is that they should clean up after them and that it can be done with minimal effort.'
^Uh-huh. I'll have you ride with a pitchfork, ride along, dismount, clean up the manure, then somehow manage to mount up again, while holding a pitchfork.
I could list more, but I'm not going to push it any farther. I think this sorta proves that all of us need to have a more open additude toward riding on shared trails.