Ben:
You're looking for someone to tell you that bunkers that do not come into play for better golfers are superfluous? I'm sure there are plenty of people (who hopefully are getting on in years now) who would be happy to tell you that.
They're the ones who have removed many of the bunkers of some great architects (ie, Donald Ross) over the last fifty years. Their reasoning is if doesn't effect their game it doesn't have any point. Have you ever heard of a more selfish attitude and a more short sighted one?
This design stuff, even from a guy like Ross, is probably not an exact science though and there is much to consider otherwise. It's likely that even Donald Ross did not sit on a particular hole or with his topo and agonize for hours if a bunker should go here or there for some 28 handicapper. There is probably much more than we realize or would like to admit about the practicalities of construction methods, certainly in the old days.
A month or so ago GeoffShac speculated on here that the reason for a particular bunker here or there might have strategic value and it could also be an integration feature too, I suppose, but it could just as likely be a result of just grabbing some fill that was needed nearby.
The original top shot bunkers at my course, for instance. Looking at some of their sizes and shapes it appears to be about the same amount of removed fill as it took to construct the tees that were only 100 yards behind them!
Or even look at some classic green structures like #3 Merion, even NGLA's Redan, or the much more common green like GMGC's #5 on the usual sideslope. The enormous bunkers that are generally to one side of them are probably as much to provide what it took to prop up that side of the green for a necessary grade for putting, to provide the necessary fill it took to do it as much as strategic value.