When it comes to motorcycles I'm definitely old school. I owned a '66 Triumph Bonneville 30 years ago. I currently own a '13 Royal Enfield B5 with an aftermarket pipe on it. It still looks, sounds, and feels like a vintage British bike. I also have an '02 Kawasaki Vulcan 750, which is a 1985 design, came out the same year as the original Rebel. The only thing I really don't like about it's looks is the engine. It's liquid cooled, with no fins at all. It looks like a water pump or an air compressor to me. When I saw the "new" Rebel, I sold a Kymco scooter I had gotten bored with, and bought a brand new '16 Rebel. It's my third one. I just can't seem to stay away from these wonderful little bikes, even though I'm 6' 220.
Of the current Japanese bikes, about the only ones I like, besides the "old" Rebel,are the Honda Aero 750, Honda Spirit 750, Yamaha VStar 250, VStar 650, and SR500, the Suzuki TU250 and S40 (Savage 650) Though not a cruiser, I also liked the new Honda CB1100. The Honda GB500 and Kawasaki W650, Vulcan 500, Vulcan 800 and 800 Drifter were also very nice bikes. Definitely not a fan of the "new" Valkyrie, Vulcan S, Bolt, and Harley Street. I feel cruiser style bikes need to look the part, and there is nothing "modern" about that style. The whole cruiser look is based on vintage style. Therefore, cruisers never really go out of style. Just look at the new Polaris Indians. The Scout looks a little odd, but the big ones look almost like the real thing.
However, it could be that younger riders don't really care for vintage style, they want modern, and the riders who do appreciate vintage style bikes are getting older, and not buying enough of them to make them profitable. I heard the Yamaha SR400 failed because it lacked an electric starter. It's hard for me to imagine anyone not being able to kickstart a 400cc bike.