He doesn't offer an explanation for it. Why has this changed? Why do police operate this way?
Suddenly they are cowardly? I doubt it.
I think it's because it has become ingrained in the SOPs. And it is in the SOPs because of the prevalence of deadly weapons in the general public.
Shoot first, ask questions later. When you operate in high risk circumstances, this is how you adapt.
It says it in the bible somewhere, doesn't it? The love of guns is the root of all evil. ;-)