Ever think about what would happen if an NFL, NBA or NHL team had a guy on their roster as bad as Brad Penny or Derek Lowe? There are countless examples of guys who simply aren't good enough to be Major Leaguers -- most of them pitchers -- yet teams continue to trot them out there in embarrassing fashion. They eventually get released, only to have some other team pick them up and put up with their bullshit.
Why is this unique to MLB? The talentless always find a home.