I think you guys hit it on the head - there isn't only ONE keyboard but MANY.
You can say "Oh this is the best keyboard I've ever typed on! I can sell the rest."
And maybe you'll be satisfied for some time but you will always eventually crack.
To each their own, not everyone would share the same taste. Just as well I guess most of us are searching/longing for the "perfect" keyboard.
Not all people maybe comfortable with selling their other keyboards. Some of them may like to do keyboard rotation in a bid to prevent excess wear and tear on one particular keyboard. Others I guess one could crudely say "hoard" their spare keyboards as such keyboards maybe rare (or eventually will get rare). Just as well I am sure one can find collectors of various sorts. They have their own reasons.
Eventually crack is part of the game, almost everything involves money. Not trying to grill you for this but I am sure people have constantly moaned about the fact that they have been "wallet hacked". I am sure these are the tell tales signs of one's seriousness to be a collector of some sort.