First of all I don't care about how controllers function, I imagine alot of players that want improved KB/M support are the same way. Outside of controllers there isn't much need for target locking in the first place.

The issue that alot don't understand is that it's not intuitive or optimal to ever need to take your hand off the mouse to cast a spell let alone anything else. It's called Keyboard and Mouse for a reason. Trying clicking on your target to confirm a target to see how much of a pain in the rear it is.

Blizzard doesn't want the interface getting in the way of actually playing the game, something alot of developers downright fail at. I miss my 3 stack of bars with all of the buttons having ctrl/alt/shift bindings rather than clunky page switching. Every ability I could want 1 button press away.