You forgot "These people aren't really bright, are they?"
Seriously, man. Half-ruin your game experience just to get that next uber l33t sword? I mean, in games with any kind of economy, this makes no sense. Because some people want instant gratification, it makes it harder for the next person to buy what they'd like. Which increases frustration with that person. Which makes it more likely they'd buy it that way, too.
See the cycle there?