In comparing the Diavel and Rocket, the Diavel has an engine that is literally wrung out.... Desmodromic valve train, high compression pistons, super light construction, chain drive etc etc etc. It's made to rev and generate power. Not sure it's longevity is sacrificed doing so...
The Rocket engine even with close to 11 to 1 compression is mildly tuned. Compare the 2.5 liter engine GM used for years. It was rated at 196 hp and 186 ft/lbs of torque in a family car as a base engine. It ran for hundreds of thousands of miles.
Why is Triumph so hesitant to unleash their engines where Ducati isn't???