I think buying Morata makes a lot of sense. It was always unlikely that Wenger would dump Giroud just after a season. And unless we got someone like Cavani which itself was difficult buying someone like Morata seemed like the decent option.
It means genuine competition for Giroud. Not just in terms of position, but that Morata is more of a false 9/team-play striker than say a Suarez/Sturridge kinds.
Lastly if it means blowing up cash on a player like a Sanchez or a Sharaawy i am all for it.