No single weapon is perfect for every situation.
That's the other great myth that the American military has been laboring to make true... that there is that ONE HOLY WEAPON SYSTEM that will be all things to all soldiers.
Well said, and quite true.
it is ...interesting, for lack of a better word, how the US military (and the included civilian bureaucracy cannot seem to realize that one cannot escape the laws of physics on their word alone.
Until we reach the next level of technology (phased plasma rifle in 40 watt range?) there is no getting around the physics. There is no free lunch.
One cannot make a weapon that is light, short, handy, low recoiling, easy to fire on automatic, AND is powerful and long ranged at the same time.
Look at what we came out of WWII with, and carried into Korea. The 1911A1 pistol, the .45acp SMG (tommygun or grease gun),the M1 carbine, the M1 Garand, the BAR, and the Browning .30 cal machinegun. Something for about every situation.
With modern assault rifles (AK and AR designs primarily) you cover the SMG and carbine slots pretty well. So that reduces the needed weapon types by one, and modern tactics have eliminated the long range rifle as general infantry issue, but it is still needed and useful on the battlefield, so it needs to stay. Newer designs of belt feds have essentially replaced both the BAR and the old GPMG in one weapon. So, another savings there.
We tried, for a while with a separate grenadier. Remember the M79? (blooper /thumper?). Then we went to the M203, mounted on the M16. Ok, better than the rifle grenades of WWII, but, at the cost of another weapon system, and all that goes with it.
The M14 was an attempt to reduce the number of needed weapon types. In that, it failed. Political reasons meant it never got the chance to have the "bugs" worked out, but it would likely have failed anyway, simply because it just wasn't the right platform to do a good job for ALL the things it was hoped to be.
I consider the M14 /M1A to be fine rifles. I will always have a special place in my heart for them. But they are part of the past. Outmoded?, sure. Obsolete? ok. But they still do work. And like the Mauser 98, or a vintage Winchester, they still do what they did then, and just as well.