The platform has its merits. Probably I could cut this group in half with a scope?
As a "battle rifle", does one really need better accuracy? That said, the AR-308 that I built in 6.5 Man Bun will consistently shoot 1/2 MOA and 1/3 MOA with anal retentive reloading and 140 RDF's or ELD's. However, to get that accuracy it's heavy AF too.
M14 gets bad press as a transitional rifle, but if I had to choose one to drag in the mud it would be the M14/M1A over a M110/AR platform. Conditions that would easily jam an AR-type bolt won't bother the M1/M14 bolt. Hell, they will practically go into battery if one of your digits is in the way. How many AR bolts have drawn blood? The answer for M14 bolts is easy- all of them.
For any type of long distance accuracy work, I'll agree that you can put a lot of lipstick on a pig but it's still a pig. Though the triggers can be tuned for reasonable improvement, the M1/M14 trigger system can only do so much. There are beaucoup choices for AR triggers, and with a top shelf trigger and barrel/bolt combo the AR will win the accuracy contest every time.