Martingales are not the spawn of the devil, ok? Not if used correctly. They are NOT useless and they are FAR from abusive. Using it to tie a horse's head down? Yeah abusive... but so is yanking on a lead rope over and over and over for no reason... It's not the equipment that is abusive, it's the hands that it is used in.
I use it on my mare because she is an extremely talented and powerful jumper who gets enthusiastic once in a while and flips her head (only when going 3'3" and above it seems) and I use one... on occasion.
But my point is, just because one person uses it incorrectly, don't think that that is how the training aid is actually used. Because usually, it's not.