Sooooo, I'm not a shill for the company, but they seemed like really good guys when I met them at the New England PRS match and I hate to see them get beat up here. The Industrial Designer was shooting the Fix and all of the folks from Q that came out for the awards (including Brittingham - have you ever seem anyone else who owns a company show up at the prize table?) were very friendly and approachable. They let all of us shooters finger the hell out of their baby and answered a lot more questions than I expected from a company that is on the leading edge of a very competitive marketplace.
That said, this website caters to a pretty unique crowd. I seem to recall from previously released info on the Fix that a couple of the key players in the design team were former operators at a high level. Now, I don't know what their experience or knowledge of PRS shooting is, but it seems pretty reasonable to me that the idea of using the ubiquitous (let's face it, there must be orders of magnitude more AR-15 magazines out there than .223 Rem AICS ones, and I would venture the same is true to a lesser extent of the 7.62 mm brethren) would have made a lot of sense to some guys who's world view was shaped by operations (where I would imagine a single magazine system for all their weapon systems would be tremendous a bonus.) Add to that the intention to make this the everyman's rifle (whether or not the price is YOUR idea of the everyman notwithstanding...) it makes perfect sense to go with a known commodity for magazines.
Now the issue most of us HERE ON THE HIDE care about is COAL. But honestly, how many guys who drop more than $3000 on a rifle actually reload? Not just your buddies, or what you think the shooting community looks like. Think about all the guys with slick hunting rigs that go on one or two high end hunts every couple of years. Or the weekend warrior with the latest and greatest LaRue AR. There are probably more WAY folks like that out there than PRS-focused folks who inhabit the Hide. So, yeah, I can see this being a very acceptable market decision for them.
At the end of the day I see the magazine decision as bad FOR ME because of how I would want to use the rifle. Especially for the .308 bolt face models. But for a .223 bolt face model, I might just be able to get behind a very slick looking, innovative but not perfect new design. That uses the metric (I'm Canadian) shit ton of AR mags I have.
YMMV.