This is nothing new. The M-16 has had it's share of failures in the battlefield too, and that is what the M4 is based on. What is unbelievable to me is that after 12 years of the M4 and how many decades of the M-16, that we can't give our troops a better battle rifle.
What is stated here is purely my opinion. The problem with the M4 and it's variants is that it's design doesn't meet the requirements of reality. It's like using a corvette to go four-wheeling. These M-16/M4 weapons are made to be light, and use ammunition that maximizes firepower in terms of rounds of ammo that an be carried. The gun also has relatively tight tolerances that doesn't cope well with sand, grit and other elements that will get inside a guns action and render it useless. Also, the gun can't get rid of the heat fast enough under full auto fire. On top of this, the Army has chosen a round that is substandard in my opinion. The 5.56 works fine against woodchucks in rifles that have 24" barrels, but with the 14.5" barrels many of these rifles have sacrifices too much velocity. Remember the soldiers fighting the Moros in the Philippines? They found out how badly the .38 faired and clamored for .45s
Don't get me wrong; Colt has made some fine firearms throughout the years. The M1911 is among the finest, and it's too bad they can't do the same with the M4/16. Make is simple, reliable, and idiot proof. On the other hand, if you must go with such a substandard firearm, at least give Ruger or some other company a crack at making one that works better. If it were me, I would choose something else.
If it were I, I would use the AK-47. It's what our enemy uses, it's so reliable and simple that it's a job to get it not to work. Also, you could use any contraband ammo found on the battlefield. If that isn't palatable, HK makes some nice rifles based on the G-3 design. The HK91 and 93 are way better, and even the HK416 is an improvement. A SOCOM M14 would be nice as well, but I imagine our boys can't carry anything heavier than a loaf of bread.
How did we get here? My guess is lobbyists and other glad handing palm greasers found it more important to get a government contract than actually produce something that works well. A quick fix if they haven't thought of it is to use receivers and bolts that are plated with a nickel-ceramic compound that doesn't require lubrication and improves heat transfer. It's also easier to keep clean. Of course, it would be easier just to buy a couple million AK-47s from the Chinese. I am sure they have a few to spare. Below, the SOCOM M14, John Garand's design at its finest.