Having the same problem as well. It feels like the inanimate objects have a bigger "box" now with legendary ping.
While the enemies cannot be targeted things like radios and forklifts can still be hacked through obstacles.
I'm not certain, but I suspect that the change was intended. I am certain that the original functionality of Ping was intended, and is the main thing that made the Legendary version legendary. (Side note regarding Tech weapons: I agree that tech weapons shooting through walls is ridiculous - I removed that ability with a mod.)
I'm alright with Ping working either way, although I thought the original idea was pretty cool. Now I just hack cameras through the wall, and use them to hack people that I can no longer hack through walls.