I have been mugged for my primary twice, not my buddy and from behind, and it would have been a bad day in each case if I was a novice diver at the time. If the diver had been trained to take the safe second it would have been a nonissue.
I can see this from a couple of perspectives. I won't say one is 'righter' than the other. I may have a different preference.
a) I understand the point that you are making, about training divers to take the alternate air source. That is what has been done as long as I have been diving, and is still done today in the vast majority of cases. That is how I was taught. That is how I was taught to teach. That is how I have been teaching for many years. I would frankly be surprised if the divers that 'mugged' you were trained any other way. Yet, they went for your primary. I suspect that a stressed, possibly panicked OOA diver is VERY likely to forget all of that training, and go for whatever they can find. I am actually not at all surprised they went for your primary; at the same time . . .
b) I have to think the 'not out of air' diver is in a
much better situation to both manage an OOA situation, AND respond to the unexpected. I also think training for the prospective donor has a higher likelihood of being recalled, when needed. So, I can just as readily see the value of training divers to go for their alternate as soon as somebody mugs them for their primary (or their primary gets knocked out of there mouth, or pulled out, etc.).
So, in
my case:
I am perfectly happy to have OOA divers mug me for my primary. In fact, I invite them to - that is why I put a yellow purge cover on the second stage that is in my mouth. Frankly, I dive in reasonably good horizontal trim 95% of the time (alas, I am not perfect), and I would be surprised if the OOA diver could actually find an alternate in 'the triangle', irrespective of how securely it might be attached. Now, with my configuration, they can actually find that alternate pretty easily - right beneath my chin. But, why would they bother reaching for that, when there is a big, fat, juicy, second stage with a yellow purge cover sticking out in front of my face, saying 'take me'?
Therefore, if you are OOA, and diving near me, whether you are my buddy or not, and you go out of air - take my primary (please). I am trained, and ready. You can be sure it is a good second stage (hey, I am using it as my primary), and you can be sure it is working (hey, I am breathing from it). And, I know EXACTLY where my alternate second stage is - right there beneath my chinny-chin-chin on that bungee necklace. I also know it is working, because I test / breath from it periodically throughout each dive.
So, ♫ you take the primary, and ♪ I'll take the alternate, and ♬. . well, I may not end up 'in Scotland a'fore ye', but both of us will probably end up safe and sound on the surface, around the same time.
As for divers not stowing the safe second properly and dragging it in the sand, the issue of not having enough time in OW to insure the production of a good thinking diver might come up.
YES!! Notwithstanding all of the efforts of training agencies to establish standards, and train instructors in applying those standards, the excuse of the economics of dive training seems to prevail in some cases. I may not like it. But, I can't say it isn't reality.
Frankly, if everyone was well-trained, and everyone followed their training, this discussion would almost be moot.