I am all for the right to protect your own home. Many states have laws that support the old english common law "castle" doctrine (your home is your castle, you have a right to protect it).
Beyond that, I see opportunities for serious abuse of the "stand-your-ground" laws, either intentionally or accidentally. Citizens have no training in how to act in public scenarios like the kid with a knife robbing a grocery store. A successful outcome may result or it may result in a deadly overreaction.
THere is a case in Florida under investigation:
In Tampa, a tow- truck operator shot and killed a man he said was trying to run him over and used the "Stand Your Ground" law as a defense. The district attorney is evaluating other forensic evidence and eyewitness testimony that the shots came from behind, and therefore were not in self-defense.