I think until someone does a large scale test with a sample size big enough to subdue the "noise" we'll never really know what quantifiable effect blueprinting has. Here's my argument, though...
1) How many negative reviews have you seen about Criterion "Remage" barrels, or any flavor of Savage, Tikka, Ruger, etc. "match grade" (higher quality) pre-fit barrel? Whether they plug into a factory Savage, Remington, or Ruger receiver, the result is almost universal. I'm not bullshitting in saying I've never seen a bad review or someone saying they're having trouble getting them to shoot. The ONLY exception to that is a guy that was screwing a Remage into a trued receiver-- obviously this isn't the fault of the receiver, the truing, nor the barrel. Just an example of probably dangerously loose thread fit. The only way these barrels work is if the receiver threads haven't been touched, and I'd argue that most guys don't true the face or lugs. Consistently sub-1/2 MOA results are had, often better. Is that at Benchrest level? no, but then again I think most of those guys are shooting steel plates and animals and don't care to go through all the associated handloading voodoo/BS to get there, either.
2) How many "Blueprinted" receivers have you received that had the work done by another shop (and this isn't just you, I've seen it mentioned across the board on internet forums and in personal conversations) and you set it up in your fixture and dial it in to find that it's "0.0XXX out". Between changes in temperature, part flex, part movement, loose locking mechanisms in fixturing, the bushings seat differently, whatever... The work you do "as perfectly as you can" can be taken by someone else and shown to have some sort of run out-- often times I've read/heard of just as much or more than what is typically present in a factory receiver. Now regardless of who's work is closer to being "perfect", both your typical blueprinted receivers and the other shops' blueprinted receivers produce tiny groups... The same can be said about custom receivers. Some smiths say they don't always check out, but if someone buys a custom receiver and just screws in a barrel without ever checking, nearly universally, they all shoot tiny groups.
So like I said, until someone proves conclusively that a factory Remington action with everything else as equal as possible is guaranteed to shoot distinguishably worse than a blueprinted action, I'm set in my opinion, right or wrong. Also, I think once someone finds out WHY that happens, it would be able to be measured and corrected IF it needed it. I also think the person demanding benchrest precision out of a M700 is a rarity these days. I think there are just a handful of things that really matter, and the rest is peace of mind, theoretical improvement, and "we've always done it like that".
Everyone is scared of the what-if. "What if I have this new fancy barrel installed and mine is the one in #### that shoots like shit without blueprinting? Well, I might as well blueprint it anyway."