Why don't all members of the Air Force have to be fully qualified to be a rifleman in case of hostile events?

Air Force DEFINITELY should! The ROE has changed since Desert Storm and the enemy DOES NOT CARE what branch you serve! I tell my other half that I wished I was still in and the Training NCO for their squadron...I would piss them off with my sole mission is to keep them alive!

The 7.62 round is color blind, it only knows the color of your blood...red.

Why any airman wouldn't ever consider the possibility of having to use a weapon to either defend himself, the airbase, or both is unconscionable to me. As a retired soldier, I've reflected on this occasionally and always came up with the same answer, UNACCEPTABLE. Back in the days of the Cold War and living with the apprehension that Ivan might get a wild hair up his backside and come storming through the Fulda Gap, most Army units would be engaged in stopping that assault whilst air bases in Germany were ever vulnerable to Spetnatz and other commando type attacks. Air Force SP may be trained to engage these forces, but they are totally understrength to offer much deference. Even Army maintenance and other support units have the means to resist and offer up resistance. To have personnel without general knowledge of small arms, i.e., M4/M16, and sidearms is totally inexcusable. Don't even try that lame excuse, "we're technicians, not infantrymen" on me. Army mechanics, logisticians, and others, aren't either, but would put up quite a fight. You flyboys don't have to be John Wayne or Audie Murphy, but at least know how a magazine goes into your weapon and which end the bullet comes out of.

I was in the USAF from 1966 to 1970. We all had an extensive class on the M16 while in Basic Training. We handled it, stripped it and cleaned it. Then we spent a day on the range with it. Each year we were required to qualify with it. This was for everyone, at least everywhere I was stationed. I'm sure this was far, far less than members of the Army and Marines, but we were no strangers to this weapon. For those of us who grew up hunting, I would imagine we were also proficient with it.

I was Navy (weapons), then Army ( Cav Scout & ABN LRS-Det) , then Air Force Guard and Res. My other occupation during my Guard years was Law Enforcement, weapons and tactic instructor. My humble opinion is that the Air Force has spent the last 60 years trying to bury much its US ARMY beginnings. I noted an under-culture that looked down upon the nasty and dirty parts of war. Many support units treated bi-annual or tri-annual weapons qualifications like the Black Plague. If you started to talk to them about fire teams, then you might as well be speaking in ancient Icelandic. Of course things become real when your M-Pool vehicle mechanics find themselves acting as truck gunners on convoy duty. Some from our local Air Guard base did just that and they later stopped by the SP shop to say thanks.
If a self-defense culture is to be re-introduced into the Air Force, it will have to start in basic training, and be re-enforced via exercises in which the base is over-run and key facilities are targeted. ( and not relying on the SPs to arrive at the clinic to save the day. )
But as it stands now, any time for real training will likely be wasted on some sort of touchy-feely social engineering training.

For most of the Air Force it's true, very little training with a weapon. Being in a Combat Mobility Branch it was different.

Perhaps things are a bit different now as there aren't really "front lines" any longer. We can expect no safe spaces in future competition and warfare. But the USAF Security Forces are very good, in some ways perhaps better than the Army MP's. Mind you, they're both great. I agree that all military personnel should be qualified with a self-defense weapon. My strong personal preference is for a .45 with knock-down powerBut not everyone should be carrying an M-4 (or in my day, an M-16 or CAR-15).

Because you will spend most of your time sitting and being idle. The Chair Service depends on others to aid them while wearing out chairs.

I was a flight medic, 1977-2000. I qualified expert on the M-16 and M-9.I also completed Land and Water Survival training. I was considered a non combatant.

You are absolutely correct. When i joined the AF in 1950, we had M-1s and went to the range a couple times. I though we should have been at the range every day. Every member of the military should be able to handle a rifle and/or a handgun. I fired a .45 once at the range. How ridiculous. For God's sake it is the military after all. I am now 88 years old and go to the firing range every week and can shoot the eye out of a squirrel at 50 yards.

I went through Basic Training in 1965. We had to qualify and earn the small arms ribbon. We spent time with the M16 on the range and breaking it down cleaning and reassembling. When did that change?