The general public is still largely unaware of CR123A cells, so this doesn't seem like the full explanation to me. I also think that non-enthusiasts are unlikely to invest in the li-ion platform, yet I know lots of people who use NiMh AA and AAA cells. A 1xAA light fits nicely into their existing platform.
I've seen 2xCR123A lights for sale in these stores, but never a 1xCR123A, so as far as the general public is concerned, CR123A lights have no size advantage over a 1xAA.
Personally, I don't actually know enough of the "general public" to know if they're familiar with CR123s. They were used to power flash-bulbs for film cameras for a long time, but how many people encountered CR123s in that context, I don't know either. I
can say with confidence, however, that the "general public" has gotten used to the idea that fancy electronics use special types of batteries, because their smartphones and digital cameras and computers and lord-knows-what-else all have special types of batteries. So while the "general public" might not be familiar with CR123s specifically, the requirement to use a special type of battery to run a super-bright flashlight would not come as a huge surprise to them.
I think that it is reasonable to claim that 1xAA is a better format for scavenged batteries than 1xAAA for the following reasons:
1. AA has 3x the capacity than the AAA, so unless you're more than 3x as likely to find AAA cells than AA you will still come out ahead energy-wise with AA. Similarly, you can go 3x as long before you need to start looking for scavenged cells.
AAA-powered lights use less power because they're designed around lower-power batteries, so the runtime for AAA-powered lights works out much better than the 33% that the math suggests. In a SHTF scenario, the length of time your stash of batteries will last is more important than number of lumens your flashlight can generate -- hence the existence of the Pak-Lite. Furthermore, it seems quite possible to me that finding AA batteries could be at least 3x as difficult as finding AAA batteries, because of how popular AA batteries are. They are the first batteries to be subject to hoarding during natural disasters. I don't even use AA-powered flashlights and even I have a stash of about 50 AAs for various devices. CR123s? I have a box of 12 Surefires that I haven't touched in a couple years. AAAs? I have a stash of 20, and I don't even remember what I originally needed them for.
2. AA lights can use any AAA cells you find, but not the other way around
I've never tried this, but I assume it would require an adapter which is electrically conductive along its length but electrically insulated across its diameter, which the "general public" would probably not have on-hand. I can imagine MacGuyvering such an adapter from paper and a piece of pencil graphite, but at that point we are no longer talking about the "general public". In any event, in a SHTF scenario, your best bet is to have a spool of wire and some tape, so you can make any battery work with any device.
3. AA lights are easier to keep track of (AAA lights are so small that they tend to disappear with alarming ease)
If your life depended on a flashlight of any size, you would make very sure to keep track of it. Also, if we're talking about a SHTF scenario, the smaller size of a 1xAAA light means it would be easier to conceal from people who might want to steal it from you for their own use.
But really, I just happen to prefer 1xAA since it falls in a convenient sweet spot that no other battery format does:
1. large enough to handle easily with gloves (AAA fails, 1xCR123A often fails)
I have never encountered weather so cold that I couldn't take off my gloves for 30 seconds while I change a battery. You're talking -50°C if you're concerned about frostbite in such a short period of time, and in such low temperatures there would also be problems with the batteries freezing internally and not working.
2. small enough for easy pocket carry (3xAAA fails, 2xCR123A often fails, 2xAA often fails)
I agree regarding 3xAAA and 2xAA. However, I find the in-pocket difference between 1xAA and 1xCR123
variants of the same flashlight (such as the Olight S1/S1A) to either be unnoticeable, or to favor 1xCR123 due to its shorter length.
3. light enough for holding in mouth when necessary (2xCR123A fails, 2xAA fails, 3xAAA fails)
I had to switch to a headlamp for this purpose, because holding a flashlight in my teeth for longer than a few seconds inevitably gives me TMJ that bothers me for days afterwards.
4. commonly available battery (CR123A fails)
Depends where you live. Where I live there are CR123s for sale right next to the AAs in all my local stores. There are
more AAs, yes, but they are also the first to sell-out whenever we get a snowstorm, to say nothing of a SHTF scenario.
5. commonly available rechargeable battery (CR123A fails)
I guess, but rechargeable cells are only useful if the electric utilities are up-and-running or you have a car charger and a car full of gas, and neither applies in a SHTF scenario.
6. battery commonly used by other electronics (CR123A fails)
This is precisely why CR123s will be less difficult to find new than you might imagine, even if they are harder to scavenge from other devices.
7. enough capacity to prevent constant worrying about capacity (AAA fails)
I don't constantly worry about battery capacity, and I certainly hope you don't either; that sounds like a supremely annoying bit of minutia to worry about.
8. no worry about matching cells (all multi-cell formats fail)
I also prefer single-cell lights, though I don't generally worry about mixing new and used cells if that's all I have. The warnings on battery packages about mixing new and used cells are 1% valid and 99% legal butt-covering.
