I imagine it FEELS as though it should have no bounds. If you’ve been wronged enough to seek revenge, you probably feel like anything you do to revenge it will be entirely justified.
Revenge must feel a bit like the first stages of falling in love wherein nothing matters but the person who continually occupies your thoughts. Love wants no bounds on it either in those first flushes.
But…society does require some boundaries. We don’t really want to see every pair of new lovers going at it in the street. And we definitely don’t want everyone who has been wronged going around and seeking revenge. Revenge should have more bounds than most other things, really.