Very true about politicians...however...
There is a huge difference in the effect, or the intention of political interference before and after WWII.
In general terms (and there are, of course exceptions) before the war, the great depression, saving money was the major priority. Most often the answer to the military was "no, you cannot have new toys!", and even went to the extremes of not allowing the military to test their weapons, because of the expense (like torpedoes), which had clear unsatisfactory results when we did gio to war, while after WWII, the military often got what it asked for, and in the case of the M16, got it rammed down their throats, whether they wanted it or not. The pendulum swings, and we are today still more on one side than the other.
We fought the early part of our involvement in WWII with a lot of our major weapons systems being inferior to those of our enemies is many aspects. Our small arms measured up, and beyond, but planes, tanks, torpedoes, bombs and many other things turned out not to be as good as we assumed they would be. We did overcome this, but the time it took, the cost in lives, and the missed opportunities (which added to the cost in lives in the long run) left a lasting impression on the military, and to a degree, the American people. Today, we have a national mania for giving our troops the "best available", and yet we still fall short in many areas, sometimes because we do not understand what will actually be needed in order to give our troops the best, and sometimes because the people whose job it is to figure it out and see it done just screw up.
The M14 got its legs cut out from under it by the same political forces who held up the M16 as the best thing since sliced bread and canned beer, and kept it propped up against all complaints. Both weapons have their place in our armory, neither one is the best for every possible situation. The M14 is a fine rifle (which the Army screwed by trying to make it a SAW) and the M16 is a tolerable assault rifle (now that the bugs are finally out of the gun/ammo combo). The AK is an assault rifle (under the proper definition, not the legal one), and as such a direct comparison between it and the M14 is flawed. The only point the rifles have in common enough for a valid comparison is the bore size, .30 caliber!