Logical fallacies:
1) Pens needed someone in the top-6, and Brenden Morrow is someone - I believe the Penguins need more skill AND grit throughout their lineup. But needing someone and getting the right someone(s) are two different things. Brenden Morrow of 2013 is no longer the kind of player the Penguins need. His skating on Geno's line is going to be a comedy, for opposing teams. He's going to anchor that line, in the most unflattering way possible.
2) Having a glut of D prospects makes it okay to trade them - The Penguins should absolutely be looking to make deals that see them fill holes with their assets. But undervaluing an asset you're selling while simultaneously overvaluing the asset you're buying is horrible.
Mark Cuban would never pay $1,000,000 for a Civic just because he's rich and needs a car.