Don't hate the player...hate the game.
I try not to get too stressed about the WDW ADR games, but I do understand because I've been in the thick of a heated hunt for a Chef Mickey, PPO BOG, and a lunch SCi-Fi for the perfect time. I did once get pixie dusted a coordinated PPO BOG drop from a stranger on the TP forum - that was awesome.
The hoarding might not be all malicious. WDW allows it - not saying that makes it good, or right, but there might be all kinds of ppl that just book a ton because they don't know what their plans will be, and if Wally allows them to book a bunch, then, it just makes sense to do so. Some might not have the ability to understand that other ppl might want a reservation they are holding, since you know, there are no other people in the world besides them.