Why are you arguing for crap 50s tech?
Not crap, but indeed obsolescent. When it was all that was available, it's what got used.
A follow-on question would be, are the reported problems with AR-pattern 7.62 rifles really hardware, or software?
Back in the 90's, when there was the wholesale replacement of M14 pattern rifles with AR15 pattern rifles in NRA competition, there was a push into AR10 type match rifles because people luv them the 7.62x51, because they're mentally stunted, insecure, servile goons who can't think for themselves. Loading the 7.62x51 with heavy 190gn+ bullets where it starts to perform well, beats the living Hell out of the M14 platform, and doesn't make the AR type very happy either without adjustable gas regulator. There were a lot of teething problems, as should be expected. However they have been overcome by this point. Also at this point, the smart thing to do is to use a 6.5 Creedmore in the AR10 platform, since it performs so much better than the 7.62x51.
In the bolt gun area, I currently like the 6.5 PRC, and if I wasn't so committed to the 7mm platforms I would get one. I may well sell off some hunting rifles, and get a Ruger Precision 6.5 PRC, because that's a very nice entry level setup. S/F....Ken M