From the manual:

MLB teams can't afford to spend more than a certain level before having to trade higher paid players for lower paid and generally younger players. The PB Value limitations will mimic that situation in our PB Traditional Leagues. The Limits will increase parity and make some pennant races more interesting. We understand that certain successful managers will be coerced into trading away talent to meet the limitations, and regret any inconvenience or pain.

Really? You guys actually regret the inconvenience or pain? That's awfully nice, but I think the rule makes perfect sense. :^)

Or maybe I'm just a bit tired at the end of a 12 hour shift at 6:30 in the morning.... :^)