OP, I totally get where you're coming from with the "poor boy" stuff. I bought a young horse a couple years ago that came from a crappy place. She was thin, full of parasites, and quite timid. At the same time, my father and I bought two other young horses that came from a much better home.
Now, I am not one to dote on my horses, and I continually told myself not to feel sorry for her. But I did treat her differently (without even realizing it), and she did develop some bad habits (wasn't aggressive, don't really feel the need to go into details, though). When I took her to a colt-starting clinic, the clinician pointed out she was a little spoiled right away. Since then, I have raised my expectations, and she has met them.
I guess my point is pity does nothing positive for these horses. I know how easy it is to fall into that state of mind without even realizing it.
My little pooky-doo three year old, who is soooo sweet and non-agressive etc. recently started getting a little too pushy when I bring her grain into her pasture. I have had to take a step back, and remind her that I am still alpha and start taking a lead rope in over my shoulders to swing at her if she doesn't back up when I ask with my body language or pushing the air with my hands movement. If she doesn't move I swing the leadrope in a circle in the air vigorously like I mean it. If she then doesn't move immediately, she gets whacked on her body with that swinging leadrope HARD! Only had to do that reminder lesson twice. Now, she starts moving as soon as I start opening the gate and walks over to her spot where her food goes. Plain and simple. Then, I kiss on her and scratch her belly.