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

Airmen need to be taught weapons handling and self defense just as any other service member. This mindset the Air Force has with being behind friendly lines all of the time or having someone else there to protect them is flawed. This isn't the 1940s or 50s anymore. There aren't always going to be a clear divider between friendly forces and hostile forces. The GWOT should be a great point in case to this. What happens when we enter a war with a country's government and the opposition is a true war fighting force and they make a major attack on a friendly base? Airmen who either don't have access to firearms or aren't proficient with them will just be slaughtered. I have deployed twice and been in the Air Force for 3 years. Every time I've gone to CATM before I deployed I have seen an Airman do something dangerous because of their lack of consistent real world training on weapons safety and handling. The last time I went a SSgt (E-5) flagged the whole line of shooters with a loaded M4 because he wasn't paying attention. Crap like that can easily be corrected. Losing personnel in an attack because of a lack of weapons skills readiness can not be corrected as easily as it could be prevented.

In 1985 I had to re-qualify on the M-16 to PCS to Osan AB. I think the laws should change and we should have carry qualified citizens. I was a 307X0 Tech Controller!. Worked in the HTACC.

I was active 76-81 and qualified on pistols as member of honor guard.

It goes back to the mid '60s when they shut down all of the competitive marksmanship programs in the Air Force. I was chasing a birth on the Air Force Rifle Team at the time and of all things got stranded in Hawaii because of the decision.

I wish I had an answer but I do know the last few years I was in from 2012 to 2015, I was required to take a CBT related to the Gun Control Act of 1968 every year. I know it doesn't count as qualifying but the fact we did this every year I found it a possible waste of time. Maybe if we qualified every year or so often I would see this being a great idea.

It wasn't hard and I paid attention because I was looking for value in it, seeing that I don't own any firearms and I was in a medical AFSC that only qualifies depending on deployments, overseas PCS and/or if they are on a medical team that requires it. Was told it was an Air Force requirement, even though the training was not on a DoD site.

EDIT: I will say it could be a waste of time, because if someone violated it while they are in and could no longer carry a weapon and are in an AFSC like Security Forces that would carry one on a regular basis, the training said they could be retrained. Safe to say that won't happen in 2015, and if someone violated it before they joined, I am getting ahead of myself because they wouldn't even be able to join. And if they do get in trouble, being aware or unaware of the federal law would be the last thing on their mind or to worry about.

Isn't that why we're taught about M16s during BEAST Week?

You make a good point; however, their expertise is required to keep those air superiority and ground support aircraft operating to further the Commander's Objective.
During my time in the USAF, I was a Missile Electronics Technician (special weapons) and if the enemy forces got far enough in to threaten my crew then everyone was totally boned. This did not mean I wasn’t a good shot or could not handle the weapon, it just wasn’t my job. When I accepted a commission with the USN and became a Surface Warfare Officer my mission changed to indirect support, yet at the same time as Ship’s Security Forces Officer, it was important I could effectively handle firearms to protect my ship. Even later, when I was assigned shore duty as a Naval Gunfire Liaison Officer who deployed with Marines my proficiency became even more critical since I could be expected to operate as a Forward Observer. Although I qualified as an expert with both pistol and rifle, I felt the most comfortable during the short time assigned to the Marines. I also fired more rounds in qualification in those two short years than the combined range time over my 22 yrs career.

I agree with your sentiment, and I wish the Air Force would provide more frequent weapons training

I work in a hole in the ground. My SOPs are to turtle up, continue working, and wait to either be rescued or buried alive.

They may want to think about at least some training. As a Navy Corpsman. I made sure I was trained.