It's all hoooey, the Ruger is just as good as any other. One of the big reasons that Rugers aren't used in competition is that Ruger doesn't make a single shot action. I wish they would, it would be an easy change for investment casting. You also don't see Browning actions used either, for the same reason.
There probably are inherent accuracy differences, but I doubt any normal human shooter could see the difference. That's like all the people who claim Rugers don't shoot well and that the angled action screw is a bad design. How do you explain all the Rugers that shoot well. They must be special runs or something.