Conceivably, a bad experience building those 6.5 PRCs could stop them...
From Backfire's article on the 7mm PRC:
"I was somewhat surprised by the list of firearms manufacturers who are not yet jumping on board with the 7 PRC. Tikka, Browning, and Bergara are conspicuously missing from the list and yet they all chamber for the 6.5 PRC. Since this new cartridge has been announced, I’ve talked with my contacts at many of the major rifle manufacturers and have been surprised by how many of them are extremely frustrated with working on PRC chamberings in their rifles. There have been many changes to the reamer specs of the other PRC cartridges, and the tight tolerances make manufacturing difficult."