Sean,
I think my words were that carry bunkers have been reduced, and its not all black and white and all or nothing! Ditto for centerline bunkers, but I only call them cl bunkers if there is some semblance of fw on either side. And, its not really about championship golf either, IMHO.
There is little doubt that flanking bunkers have taken over the major precedence in design in the last 50 years or so. I was really just trying to explain why, and why the theory probably took hold. Its not just dumbing down. There is a reason. On the other hand, like most things, gca's probably saw the problems with carry and center bunkers and once they stopped using them, they stopped pretty quickly. At some point, someone asks why they aren't around any more and starts building them, remembering their good points. (no feature does it all in gca)
And as you allude, once we decide to do a centerline bunker like principles nose, we rethink it, putting it somewhere further out than 220 yards, at least from the back tees, etc. They can be well placed or poorly placed no doubt.
But, if designers and golfers have not preferred cen line bunkers for 100 years now, maybe there is a legit reason. Again, its not all black and white - the disadvantages to many may simply outweight the benefits to a few, or something like that. And its not all black and white as to their current use. I put one on nearly every course I do. Do I like is so well as a tee shot concept that I am going to do it another 13 times? There are many ways to challenge the golfer off the tee, and I agree that sticking with one type is wrong.
Which is why I agree with you that there are far too many courses with dull, unimaginative tee shots with only flanking bunkers to challenge.