OP, maybe you should try looking it differently.
How about instead of making it seem like people are doing this solely for attention (please, Nubbs, Hoff, sorry single you guys out, but you really don't need to pull any stunts to gain the respect you already have), consider it as people being charitable and generous, letting go of some of their personal hard-to-come-by rare collectibles at an affordable price, so that other less fortunate and actually want to use such a keycap can have the chance at obtaining it, instead of letting it collect dust in their collection.
Why do you feel that they are doing this solely for the sake of attention? Also, the people posting on the threads for the chance to buy one of these keycaps aren't exactly grovelling. How else would we determine who to sell the keycaps to, if we don't post a simple explanation of how we're going to use it? I feel it's nothing like what you're insinuating.