Mark, I definitely understand what you are saying, but I'll play devil's advocate a bit here.
"Why would one use 4 different wedges around the green if they all serve virtually the same purpose?" That's a good question, and I don't think most golfers need 4 wedges. I use two wedges, and I rarely use the pitching wedge around the green. For me, anything at 56 degrees and higher accomplish the same purpose. Seve Ballesteros often said the same thing, I believe.
I see some different short game shots around the green in the photo you posted, and it looks like a very interesting greensite. However, I'm thinking the options here are discrete and change with where the ball ends up. If the ball stays on the short fairway grass long of the green, a putt or 8-iron bump seem to be good options. The grass looks too tight for a wedge, which, by my original theory, leaves the golfer some ground game options. However, a ball ends up in the rough beyond the ground, a wedge seems like the best and therefore only option. The grass is too long for a putter, and the turf looks soft and cushy enough that an 8-iron pitched into the slope will be much harder to judge than a simple flip wedge. Thus, the golfer has more options from the wedge-resistant short grass than from the wedge resistant long grass.
On the other hand, the options short of the green seem to be more balanced. This, it seems, has less to do with the turf and more to do with some interesting ground contours. I am a bit skeptical about the non-wedge option from short of that mound, but it definitely seems a more viable option than those beyond the green.