Why do people hurt horses?

As horrible as it is, people generally slaughter horses when they are too old or no longer useful to people, or if they can't afford to keep them and have trouble selling them on.

It's for many reasons but it's usually when they don't want the horse any more.

I live in a strange town and I've heard rumors about horses being killed for things like glue, or other strange purposes. Recently, a girl shot one my neighbor's horses and scattered its bones in a church nearby. One might point to ancient obsessions with seances or necromancy; then again, by the brutal and rather obvious way this thing was done, it was done by an idiot. I found its hoof and another unrecognizable bone in a rather obvious path while wandering today. It's strange the things you find when your'e not looking.

Anyway, I think it's sick. I don't understand why anyone would feel compelled to kill such a majestic creature unless, as stated above, it was used to abate an emergency.