Honest enthusiasm isn't a crime, and, yes, there are a lot of us who would like to see an upgrade from the M4. And buying it for the Army would cost about one fighter plane in money spent.
Here's what you aren't hearing: When most of the current Vietnam vets served, they lived in an America that had 1 in 10 other citizens who had served in the Armed Forces. Now, it's 1 in 100. Most of what the public hears these days is distorted second hand BS.
Chalk me up in the category of combat trained, Infantry and MP, but my deployment was in the wire - not even inkpens allowed. I used the M16 in the Reserves for 22 years, but I learned more about it in the last 16 months BUILDING one than the Army ever taught me.
In brief: No, the M16/M4 does not have problems with dust, it has problems with soldiers who won't clean it every day, keep it clean, and kept it lubricated WET in the upper cam pin channel per the TM. Soldiers do keep the port cover closed, add a plastic muzzle cap to protect the barrel, and even bag them in high dust areas. What's not being said is the AK has the same problems, and being DI or piston has really nothing to do with it.
Magazines have been a big source of the M16's problems since nearly the beginning. What makes the AK reliable is a nearly bullet proof machined magazine that works, and what makes the M16 fail is a cheap stamped aluminum magazine that will jam if dropped on the feed lips when loaded. The fix is the Marines are using Pmags, and the Army is buying them, too. If you can't bend it, dent it, or make it hang up inside, a mag works, and there are a lot less problems with them.
Who we train to use a gun is part of it, too. Think about it, the kids you teach soccer really haven't much clue about it, they still kick with the toe, don't pass well, can't exploit an opening, or dribble downfield against 5 opponents and attempt a goal. Well, an 18-23 year old new recruit hasn't lived with a M16 since birth (like some recent immigrants who dominate the game locally,) and there's a lot to learn.
I was watching a Marine squad leader teaching his team the finer points of simply switching from carrying the weapon pointing left to pointing right - you depress the barrel to the ground as you sweep your buddy in line in front of you. Don't shoot him in the back, the guy behind you doing the same. 22 years in the USAR, I'd never seen that.
There are literally hundreds of tips, tactics, and tricks to learn, the problem being making them lifesaving habits in less than three years before someone ETS's. A lot of them don't even get the habit of cleaning the weapon daily - especially if you don't fire it for months at a time. Haji isn't ambushing us that much, he'd rather plant an IED, read up on what really kills our troops.
Switching to a piston won't fix the REAL problems, DI works just fine.