As I said, it all depends on where you are. In LA, for instance, half the city is standing water, making a boat (and a chemical wetsuit) essential equipment if you're going to try and avoid the cops. Or if you're in the Carib League, or the Phillipines, or several of the less civilized areas of the world, a boat is more useful than a van. In Seattle, having a boat means you can navigate to different islands (and out into Salish lands) easier than by going through checkpoints.
Boats obviously are of limited use in Denver, I'll agree, but in any city with major coastline and waterways, boats are like any other vehicle, they give you options. The insertion to a corp warehouse on the docks may be easier by sea than by land, yeah?