There was no targeting of the head, Aho dragged the puck behind him while staring at it and skating sideways/backwards right in Gio. Gio is absolutely appropriate hitting him. New age/old school....doesn't matter. The second a dman is supposed to jump out of the way so Aho can complete the dangle is the day I'm done. Gio should not have to make any determination or think out whether or not he is supposed to play the body. Of course he's supposed to play the body - that's the NHL. There was nothing vicious about the hit. He kept his elbow tucked. At the angle Aho was coming at him it was going to be difficult for it not to be a tough hit.
That is ALL on Aho. This wasn't a guy stepping up to crush someone in neutral ice and caught a poor soul unaware with his head down. This is a dangerous attacking forward close to the net pulling off a drag with his head down and skating laterally right into Gio's space to score a goal and Gio's sole job is to stop him.
Bleed, normally I'm in agreement with the majority of your takes. I'm also a big proponent of the physicality of the game.
However, in this case, I disagree with your characterization of Giordano's actions.
Yes, Aho has to keep his head up there and/or make a different move. Having his head down, even after glancing and seeing Giordano coming his way (you can see it in the video), is a huge mental mistake. But Giordano clearly lunges, even launches himself into the hit. The "leaving his feet" after the hit that BBA noted as something often happening with player to player collisions only happens because of this action by Giordano. He could have just as easily remained in his slightly crouched position and his shoulder hits Aho's chest/shoulder. His knee is likely at a lower profile as well, probably grazing Aho's leg below the knee. Who knows what the results of that type of collision would have been, but his distinct actions led to the injury in my mind.
I can't read Giordano's mind, but that hit looked less like it was designed to send the message, "...hey kid, stay out of my kitchen" and was more about, "...I'm gonna f*** you up cause I can". If you don't think Giordano has that in him, recall his knee on knee fiasco with Cam Fowler last spring. I believe there was another questionable hit on Kadri as well.
As I said, I don't want to see big hits out of the game, but this hit appeared designed to injure, designed to take a player out of the game. That's the part that I take umbrage with.