Uhhh….Yeah, asking if self defense would encourage vigilantism is a round about way of saying that.
Vigilantism and self defense are two totally different things. If anyone would use this as an excuse to become a hero should be punished to the full extent of the law.
Myself personally would be more worried about rioters burning down cities and assaulting people than any vigilante, since no one has been arrested for those crimes. Seems that kind of violence is acceptable to the radical left.