IMHO, where the Japanese went wrong was trying to hard to imitate Harley Davidson. The Japanese had some wonderful inline twins, inline 4's, and some really hot V4's that were just dynamos on wheels. Today, it only seems like Japanese bikes are innovative when it comes to big touring machines and sport bikes. The cruisers are all v-twins to more closely resemble a Harley. Yamaha even went so far has to start using push rods, despite Yamaha having no nostalgic reason to build a cruiser with pushrods. As for Harley's being slow, who cares? They're fast enough. I feel about as badly when faster bike passes me on my Harley as I do when a vette blows by my jeep Cherokee. If you're exceeding the speed limit, you'll be passing me, even if you're on a moped, because your chances of catching me speeding are about nil. That's not what I look for in a car, and it's not what I look for in a motorcycle.
They tried...
Honday VTR-1000 (US) / RC-51 (rest of the world)
Suzuki TL1000R
Didn't work out so well for them. Both Honda and Suzuki built V-Twins for racing, but neither really did very well against the Ducatis, so they went back to their 4s (inline for Suzuki, and V4 for Honda).
Mark
Good points.
I havent been into dirt bikes since the early 70s, and never thought much of cafe racer crotch rockets. I preferred comfortable touring bikes. BMW makes a great touring bike.
When it comes to reliability, I often think of police department motorcycles. A long time ago California Highway Patrol switched to Kawasaki - remember CHiPs? They had to switch back to Harley because the Kawasakis didnt hold up. Our local department did the same thing - but again they didnt old up. They were replaced with Harley and BMW, still running strong. They even have a few old shovelheads still on the rode.