Originally Posted by Rain Man
They'll heal eventually and won't be friendly.
I'm not saying that's a reason to finish them off, but it's a rationale.
When I was in high school, my father got attacked at work by a couple of thugs. (He ran a restaurant and they came in at night and just did a random attack.) He had to testify against them in court and they got sent to prison for a couple of years, and when it was time for them to get out it was very worrisome. We got new beefy locks on our doors and all kinds of stuff.
I told my wife that anyone that breaks into our house will end up dead because I don't want to worry about them coming back wanting revenge.