Nick Blackburn (we're comparing pitchers to position players here, but stick with me) was worth -2.3 WAR in 19 games. 98 IP.Not to take away from either player's awfulness (or your overall point), but Greg Dobbs, Joe Mather and Ryan Rayburn were arguably way worse -- Rayburn was worth -2.0 WAR, and he played in 80-90 fewer games!
Revere strikes out more and has even less power than Pierre. He has value, sure. But in the Twins' system he's a 4th OF at best. This is a trade where both sides are getting something they need, so I think both teams can "win" this trade. Revere is an elite outfielder, one of the very best. But I bet Mastroianni will have greater than or equal value than Revere in 2013, and I doubt the Phils would've given up Worley & May for Mastroianni (a guy the Twins plucked off waivers).Also I think its utterly bizarre how people call Revere a Juan Pierre clone as if it was an insult. Pierre was a really good player for a while. If Revere is Juan Pierre good for the next 5 years then the Phillies won the deal.
Don't get me wrong. Ben's great and I loved watching him play. But the Twins traded him at his maximum value and got solid pieces in return.