John,
There is a long tradition of aiming rocks or poles on Scottish and Irish holes where there is a blind shot. So if you want to blame someone, blame Prestwick or whatever course did it first, not Erin Hills or NGLA.
If you got rid of the aiming rock then the line would be "a little bit right of the closest tree". Would you then say they should cut down that tree because it helps you aim? Maybe they should cut down all the trees you can see from that tee, and flatten the hills and remove any other features that might help a golfer aim his tee shot? Oh, and you better ban Strokesavers too, because I've actually used them successfully to figure out where I want to aim based on their drawings and distance markings!
I occasionally hit some extremely wild drives, so I'm pretty experienced with hitting shots where I have to pick a spot on the hilltop in front of me or a treetop or the top of a building or when all else fails a cloud or blade of grass or even the angle of my shadow. Having to figure out my line like that is usually more accurate than using an aiming rock anyway, because I can compensate for where the pin is, where I want my misses to go, etc. But it takes me extra time to play a shot like that because I have to walk far enough to see what I can't see from my ball and then get my line figured out.
I've found that those aiming rocks aren't always aimed where I'd aim if I had all the information myself, especially on tee shots. But without an aiming rock there I'd either hit totally blind the first time or if I had time I'd jog out to about where it is so I could see the green and then find myself something to line up with. So how exactly would getting rid of the aiming rock help? The game isn't more pure, or more challenging, but it might be slower.