Wild Wing-Avocet 6/17.
Hopefully, Jeff Brauer will offer insight.
Probably just part of the trend at the time. I do recall thinking that they are safer if the greens connect back left to back left, and this one is back left to pure back, with trees blocking, so I think it's okay and haven't heard much about safety issues there.
Tom Doak makes a point about cart circulation, which was a factor here. The Japanese owner supposedly didn't speak English, but asked through a translator why the cart path on no. 6 crossed the fw somewhat short of the green. When I explained it couldn't go behind the double green, unless we raised it and built a tunnel, he laughed heartily before getting the translation, sort of tipping his hand that he spoke more English than he let on.
OT a bit, but another potential safety issue was on holes 3 and 4. Willard Byrd had left a 400 foot or so wide corridor, originally planned for houses, but we needed to use that for golf holes. Anyway, I felt we could do it with careful tree clearing and a sharded cart path, in part because we wouldn't need a full buffer on the third, which was adjacent to another course. The owner flew in all the way from Japan for a one day visit, because he was concerned it was too tight, but left satisfied that it was okay. I think we were prepared to add two holes elsewhere had he not, which was okay because the Avocet didn't return to the clubhouse at 9 anyway.
As to double greens in general, I recall a magazine article during that 1990's period when double greens were fashionable, and the author came to the same conclusion as here. There were the 8 at the old course, and a handful of others in Scotland, but the 1990's US trend more than quadrupled the number of double greens around the world, or something similar.
They rarely make sense for safety reasons. I have done two 9/PG combos, but in reality, the putting green is separate with with adequate spacing, a narrow "cheater" connector just to say they are combined. Most of those were removed by the super as unnecessary greens maintenance, but I saw one stayed there, used as a greens turf sod nursery when required.