Lance -
Since you seem to enjoy the debate more than most, I will bite on this one.
As many issue knives as i saw die in the field, as many older knives as you can see in any listing of old issue knives, and those knives and sheaths were treated to resist rot, and them having tattered rotted sheaths, and chunks of handle missing, you cannot simply put it off on poor maintenance...
I don't believe anyone is questioning the validity of waxing a sheath or using some other form of treatment. What I was stating is a waxed sheath is not necessary to have a useful long lived sheath. Most of the knives you reference are factory made mass produced items (i.e. MK1's, MK11', M3's, etc.) that are obviously not up to par with a hand made Randall, whether it be in the 1940's on Tarawa, or 2012 in A'stan.
and Randalls are no different...
I believe this is where your disconnnect lies.
and i imagine quite a few Randalls died in the field too and are non-extant,
I have no doubt either, but the attrition rate relative to the mass produced items you compare them to is substantially less seeing the same service, and I attribute that to the quality of the knife.
having personal experience in what amphibious operations and jungle heat and humidity does to gear...if it were simply a matter of maintenance, everyone would still be using a kabar and the SEALS would be using a leather sheath....since Korea and beyond,
Experience aside,
Kabar's are cheap,
Randall's are not, and Kydex or similar type materials are a step forward (if you will) in durability is some circumstances, no argument there. I think it is readily apparent to most readers that the majority of gear is and has been moving to synthetic materials for quite some time. Leather, cotton, linen, etc., are not the first choice for many if not most applications, and again, it is hard to march against technology. In the end though, your comaprison is not wholly valid, as some say we should still be using the Garand. I will still take leather, and if I deem waxing is necessary, so be it.
The full tang knives are great pieces for sure, but so is a #1, #2, #3, and so on. It depends on the users preference. I have always been a proponent of SS primarily because it requires less care than tool steel. Otherwise, tool steel is more than adequate, particualry if you are a gear queer and really stay on top of your kit.
We don't know what type of maintenance or protection Vicker's gave to his sheaths, if any. While his statement about leather sheaths being expendable is
somewhat accurate, it doesn't have to be so. A little maintenance or treatment can go a long way. Didn't I say that before?