I knew nothing about guns and weaponry as a 17 year old city kid and really, didn't learn much more in the immediate years following discharge, but as I've aged and experienced, I prefer the 7.62 caliber and though I haven't fired one since my mid sixties Army days ... I did like the feel of my M14.
My two cents' worth.
IIRC the M14 was widely panned in Vietnam due to weight of weapon and ammo, plus the generally short range of engagements there.
Perhaps the conditions in Vietnam were too specific to serve as a guide for a standard design that would have to be used in a broad range of environments around the world.
However, it may be that the current change may also be in reaction to specific conditions, in Afghanistan, that are unlikely to be the case in the next place US infantry is deployed. In extended urban combat say.
The ideal would be to have a stockpile of different weapons and their ammo that can be issued as local requirements dictate. That could get very expensive, not just in purchasing all that stuff, but moreso in training everyone.
The M-14 is a great rifle.
My pastor was a Marine and was greatly disappointed when they took his and gave him an M-16.
I qualified with the M-14 in 1969 and the M-16 in 1970. Hated the latter for the rest of my Army days & since.
PS Magazine said in 2009 there still existed arsenal stocks of M-14s and that these were being issued to our troops still in Iraq. What’s past is prologue.
Years ago I bought a pre-89 M1A/M-14A semi auto. Most enjoyable to fire rifle I’ve ever owned. It was designed to improve on the M-1 Garand and that’s still the case.