Most of my training was with the M1, some with the M14. Then when I got to Vietnam they gave me one of those worthless M16s. To this day I can't bring myself to buy any of the civilian clones I see everywhere. If I were to buy any of the three for myself today it would be the M1. Kicked hard - but it hit hard and it NEVER jammed.
I believe you're not doing a valid "apples to apples" comparison per the rifles when those rifles first came out, who had them, who had issues, and how long did it take to fix those issues?
The M1 started field testing in the early 30's. The M-16?
I can shoot a 5.56x45 in full auto in a rifle pretty accurately in controlled burst (depending on the model you don't have to worry about control lol). However, in a 7.61x51, in full auto mode, I'd be lucky to hit the broad side of a barn after the second shot, let alone a .30-06 caliber rifle, no matter how heavy it was. After the second shot, an M-14 in auto mode would be approaching 45 degrees moving upward with me shooting it.
I have a 5.56 rifle in piston operation that I had over 3000 rounds through it before I cleaned it (long story, but wanted to abuse it to see what it would handle). NEVER had a malfunction and that was using some of the cheapest, dirtiest steel case russian ammo I could find. I use to clean my gun religiously after EVERY shooting. Not so after getting older. That one rifle though just had to clean it after than many rounds, driving me nuts.
Personally, I think the M1, the M-14 and the M16 are all great rifles.
Like anything in life though, when a manufacturer first comes out with a new model, odds are you're going to be working through some issues (hopefully NOT with airplanes though!).
That said, each rifle/caliber has it's pros and cons per ammo weight, gun weight and shooting distances. There really is no one perfect rifle/caliber IMO. Do think going from a 5.56 to a 6.5 or 6.8 is a move in the right direction given the current rifle platform though.
