Each to their own I reckon.
If a private plate spells name of owner, that's 'posey'! But if it relates to vehicle, it serves to de-age the vehicle. I could have had a brand new company car, but saved myself £20k over 4yrs, took the allowance instead, bought a low milage 6yr old car for a song, put a private plate on it (to keep my teenage son happy), and hey presto!
Personally, I think a Tuono plate on a Tuono bike is pretty cool. After all, it says Tuono on the tank sides, why not the rear plate!