Richard,
Congrats on re-opening Keller. I have driven by it to look, but not played. Looks great.
As to your question, I don't think back bunkers are unfair, but do know good players who at least believe that they negate aggressive play by reducing the comfort level of aiming for that, say, back left pin if the margin of error is too small. Obviously, it you ask players to take a chance on an aggressive shot, the target ought to be big enough to make it doable. The USGA slope chart suggests that this would be at least 10% depth of the anticipated approach shot, or 15 yards for 150 yard approach, etc. In fact, I would hesitate to add both front and back bunkers for that Sunday pin unless that 150 yard shot had a target at least 10-15% deeper to allow wiggle room. If shallower, they seem to prefer a little back stop mounding to effectively enlarge the target.
So, I am not in the mind that good players don't really want any feature to raise scores. In their minds, having a more than reasonable chance is a more interesting golf feature. Too dicey, and they don't really take the strategic chance we as architects are trying to tempt them to take as often as we think they should, and thus, golf becomes a more boring US Open grind type of challenge. (Obviously, if that front/back feature is done too often. Every course is different and needs its own balance.)
I also recall George Thomas' writings, suggesting a fairway chipping area over the green on long par 4's. His reasoning was that a shot long was actually a better miss than one that came up short, so why punish that? That book alone was enough to convince me to limit backing bunkers to shorter holes, in general.
I have designed some long, downwind par 4 (14 Sand Creek Station comes to mind) with a small green, across the line of play, maybe 50-60 feet deep and 100 or so wide) with a completely open front and 3-4 bunkers at the back, plus a gentle upslope to the fw in front, the obvious challenge being distance control - if you play too short, the up slope stops your shot, but of course, you don't want to go long. Another option is a lower spin shot that can run up the fairway approach. And, I figure at 470 yards plus, many average players, even from the middle tees, will be hitting wedge shots on their third, and that green fits their game as well.
Lastly, there is the old "play harder than it looks" philosophy, where the architect places a lot of bunkers left and back left, purposely putting them there to create a championship course look knowing less than 20% of golfers will hook and/or go long, and those will be better players. It was a popular theory for CCFAD courses from the 1970's until who knows when? Now still?
Anyway, you asked, I answered. That's my theory and I'm sticking to it!