Rangers fans are despising Schneider right now for the most part, especially his defensive play....and some fancy stats back that eye test up. So basically swapping Power for Schneider fixes our handedness, gets us a touch tougher....but doesn't actually improve our defensive play, especially 5v5...and downgrades our 5v5 offense.
Quinn for Cuylle is exactly what you say -- swapping ceiling for floor.
Strikes me as a trade for trade's sake while hoping we come out on the better end. I gotta think we'd get better value for Power/Quinn elsewhere.