I wouldn't call any of the bikes you listed sport tourers, with the side note the the Blackbird was the bike used by Dale Wilson for his "Hell Week" ride, 7 consecutive days over 1500 miles per day, in July 2006.
Sport tourer refers to a bike intended to be able to do long mileage in comfort, with carrying capacity for what the riders needs on his trip. The FJR (see avatar....,) the Kawasaki Concours, BMW K series, Honda's ST1300 (Pan European on your side of the ocean,) amongst a few others. The bikes are generally shaft-drive (who wants to spray the chain twice a day?), carry attached luggage, and have a generally upright seating position (although not cruiser-type --- feet are under the seat, where God intended them to be, not splayed way out front.) Generally they have longer fuel ranges than many bikes, too; I can do an 800-mile day with two fuel stops. Many of these bikes have highway-riding equipment like cruise control, and rider comfort features like adjustable handlebars and seats.
The bike you listed are a different category. They're not tourers, they're power kings. They generally have a more sport-bike riding position, but they're too heavy to be sportbikes. They handle well, but they won't run circles around liter bikes unless you've got more straights than turns. And except for Dale Wilson (who's a sadist when it comes to staying on a bike for long periods of time) you don't want to be on one of these more than an hour or two.
As for Yamaha building one...... Why? Between the 'Busa and the big Kwak, folks who want the Horsepower King at least have a choice of a couple of bikes. It's just a pissing contest, to my way of thinking....
