Roo meat makes good sense for dogs if one can get it easily and cheaply. I'd rather see what I shoot taken for that but one needs tags (Govt. issued) to move kangaroos off the property they are shot on. Each State has different rules though. It's not simply open season on kangaroos.
I know what you mean about the killing. Each time it takes a little part of a person along with it.you know? Hmm, maybe you won't understand. It's a good skill to have up one's sleeve though I guess. Like bushcraft, navigation/map reading etc. I totally get what you mean though and don't blame you, instead I respect you for choosing as you have due to your inability to do the deed.