It's Colangelo. He came to a team that was in position to draft one of Roy, Aldridge or Rudy Gay and 40 mil in cap space, and ended up with a team that lost 4 years in a row after his first season with nothing to show for it but overpaid bench players and Kyle Lowry. They will have no draft pick this year if they don't get a top 3 pick and little cap space to spend. He gave up what turned out to be Roy Hibbert for an aging Jermaine O'Neal and turned down Beasley for Bosh. He's definitely the worst GM.
At least Dumars can draft and has assets...the Raps have Kyle Lowry, DD (3 years and he can't shoot for shyt) and Jonas (who hasn't panned out yet). That's it.