Roy,
For some reason the idea of police with effective weaponry seems to scare you.
I was the first man at my newly created department in the early 1980s to buy my own shotgun for work. It rode in the car with me daily till I sold it & bought a better shotgun later on. I can't count the number of times I found myself crouching behind a car, a fire hydrant, a bush, a shack, etc, with my shotgun at 50-100 yards while the other guy had a scoped rifle that could have killed me at 200 yards. During such moments, I ALWAYS wished (BOY, did I wish!) for a rifle myself, and as soon as the department finally authorized them, I semi-retired my shotgun & carried an AR15 till I completely retired myself.
SWAT teams with all the fancy stuff are neat, but where I worked the SWAT guys were at the very least 30 minutes out, and in the meantime while somebody was making the executive armchair decision to initiate the callout & generate assembly, there us frontline guys were trying to stay alive with limited weapons.
You've obviously never been in such a spot, but I can tell you that if you were, you'd want the best life-saving equipment possible in your hands to get you home at the end of the shift.
The first cop on the scene is the one who's most likely to get an instant hostile reaction, and he or she's the one who needs adequate armament to handle it.
In my case it wasn't to be cool or faddish, it was very simply an honest evaluation of the two weapons from the sheer utility viewpoint. I worked the second largest city in my state, with lots of residential areas and open fields. With the shotgun I had 8 rounds inside with slow reloading from six carried on the Side Saddle outside, I had to make a choice of which ammo type to carry loaded (slug or buck) based on the probabilities of engagement distances, switching from buck (normally carried based on the majority percentages of encounter distances) to slug is relatively slow if greater ranging is required, heavy rounds & normally not many of them carried on the gun or the body for sustained engagements, and the relatively mediocre accuracy at distance (compared to a rifle). With the AR I had two 20-round mags on board, a very quick reload if necessary, it was shorter than the shotgun, it could handle anything from 10 feet to 200 yards using the same ammo already in the gun, and accuracy was easy and perfectly adequate out to 200 yards. Low recoil for quick followup shots was also a plus.
If you look at it as a matter of choosing & using a superior tool across the board in getting a particular job done for those whose turf indicates it, instead of a method of subjugation of "the people" by the "occupying force" in uniform, it's just using equipment better suited to getting a task completed.
I don't knock the shotgun in any way, I still carry one periodically when I'm out in the wilds and the terrain may hold large cats or hostile dog-like critters and rattlers. There is no better close-range fight stopper available to the average citizen. For city cops or other areas where the percentages indicate close encounters, they're usually more than adequate. But, for more utility I chose the AR & still would if I were still working. It's just more flexible.
Another consideration is that the shotgun recoil is not tolerated well by a lot of people in uniform today, and if you're a small to medium statured person & you hate the thing, you'll rarely do well with it or depend on it as much as you should.
Roy, it's a violent world, and regardless of your apparent fears of armed police, they need the right tools to get the job done. Full auto is seldom necessary, but the ability to defend against both the two-man armored robbery team with automatic rifles and the wife-beater holed up in the house with a deer rifle is.
As noted quite well above, the purpose of our police is to maintain order, and inevitably that makes somebody at the scene they're called to unhappy. If that somebody's unhappy enough, guns come out, or may already be out. If guns come out, it's idiotic to say "We don't want our cops to have anything better than their predecessors did 100 years ago." As an ex-cop and reasonably cognitive regular citizen now, I want our badges to make it home alive at the end of their day, and they should have the tools to help do that.
LAPD's response to that shootout, as I understand it, was initially to authorize sergeants to carry .223s. Again, the sergeant ain't the first one there, and I can tell you it's a long wait trying to hold out for the cavalry to show up.
Denis