What happened to train like you fight? I agree that initial training should be on irons and it seems like it still is, but the optics in use today are a superior aiming device. Does using a semi-auto magazine-fed rifle shit on our marksmanship heritage?
I'm all for training like you fight. Hammer drills, unknown distance targets, etc. That's all good practice that I believe most non-grunt units don't get enough of (can't speak for the 03's).
I am most adamant about the fact that basic marksmanship does not start with a glass optic. My father always taught (and I think PMIs would agree) that learning to properly use an iron sight is the first step to good marksmanship.
If you want to learn how to use a glass optic really well, it still starts with learning how to use iron sights well. Irons are much more unforgiving, and therefore force the shooter to have great emphasis of focus on proper sight alignment, sight picture, and focus on the front sight.
I think a proper analogy would be the comparison of GPS and basic land nav skills with a compass. Even if you have a GPS, if you understand your land nav you're going to make a better decision and interpret the GPS better than the guy off the street that doesn't know dick about land nav. What if that ACOG or that GPS is broken during combat? I don't like playing the "what if" game but it's a realistic contingency that must be faced.
Something else to consider. Drill. We don't use drill directly in combat anymore and yet it is an integrated part of our history, culture, heritage, and a means of teaching and preserving good order and discipline. Marksman, Sharpshooter, Expert rifleman, these ratings will mean nothing if we no longer have to earn them. I understand things always change, but the Corps puts a lot of effort into preserving itself. I continue to see it lose little pieces here and there. This competition of marksmanship is a very big piece.
And now I just wrote a much longer post than I ever intended. I get very passionate about this gun club sometimes.