It's more that when the perp shoots at the cops, he shows he is a clear danger to them, whereas if he, say, shot his friend while playing poker and is now holding the wife hostage, he has not shown a danger to the cops.
That's just basic tactics. You treat someone shooting at you differently.
I see your point, but the cops job is to protect and serve the community and our laws. My point being, that barricaded suspects are surrounded by police forces all the time. They clear the area, rendering the public at large safe and the suspect temporarily neutralized. Then other tactics are used to either establish contact with suspect or wait him out. I don’t see where any of that was done here for whatever reason. I also have heard pretty convincing evidence that they meant to torch the suspect and kill him from the very beginning. That is just not ok if that is the case. At least though we are discussing the issues now in a reasoned way. The framers would be proud.