I think the idea behind the Batman traps was that they were supposed to synergize with his ult. However, due to the insane arming time that isn't realistic at all.
I've tried to make the traps useful in GD, but I just can't see any reason to use them over something like Psychic Assault, Super Speed, or the cameras. If they lasted longer then maybe you could use them as a zoning tool, or if they were invisible after arming (Batman's should be at least) they would be much more reliable. But as is they are just a waste.