You single that out but not the guy who is defending torture?
You do not get to define what is and is not torture.
http://www.apt.ch/en/what-is-torture/
Some teenagers might beat each other silly but they are dumb kids who nobody cares about. Batman has significant influence and authority and is thus held to a higher standard than random kids.
There's no real way any of Batman's more framed methods of extracting info would ever fly in a real court room, I hope we all know that. I'm not here to tell you to stop enjoying the stories. But acknowledge it for what it is. It is absolutely torture.