Honda's retro Nighthawk 750 of just a couple years ago wasn't a big seller in the States. I think the only standard across-the-frame four UJM that had any sales success here recently has been the Kawasaki "Eddie Lawson Replica", and maybe the Suzuki Bandit. The Big Four sell a heck of a lot more sportbikes and yes, V-twin cruisers than they sell of their "standard" UJMs here.
And as Soren stated, in Japan, this "retro-standard" craze is hot, but not so much over here. Americans in the last few years have voted with their pocketbooks, and this style of bike just doesn't seem to have much of a following, and this is why Japan Inc. has been wary of importing many of the home market machines into the U.S. for some time.
And so, Mike's scenario at the Harley dealer isn't that preposterous, and the Hog salesman isn't that far off from being right.