I agree though, free is free and once you change that concept it really isn't a "Good mood Giveaway", it turns into an atypical raffle, which isn't necesarily worse, but it is different.
Some people can't handle not being given something once you put the word "Free" in front of it; they already think it belongs to them. Once they don't win, they believe that you've wronged them in some manner and it needs to be brought to justice. Then they'll nitpick your thread and continually report it until one of the mods at one point or another finds a reason to trash, lock or move your thread. At a certain point, moderators probably make things happen just to clean up their mod "to-do" list.
Is it possible that a mod just stumbled upon your thread while doing their job? I know it's a crazy concept, but maybe nobody tattled.