@xahlee @jeremiah I was in Fire Island Pines, New York, last month and I saw a fat-tired bike in the village center. Fire Island is a barrier island with motor land vehicles all but banned. (Special licenses given for infrastructure and construction purposes.)
This sort of bike works well for traveling the village's unbuilt maintenance road, and also on the paths in the dunes, and on the beach. I dunno if there's a real reason to bring it to the beach though.