Perhaps in an RX7, where the accessories don't like going 9000+ RPM, but really, it's engine vibration that hurts. The Honda engine blows itself up at over 9000 RPM sustained due to vibration. Reinforcing key parts of the engine will reduce the harmonic vibration and provide a reliable high speed engine.

Your rev limiter is there to keep you from taking the engine that high. Power runs out 500 RPM before the red anyway, so why stretch the gear?

EDIT: fixing my own apostraphe mistakes for a change

 

tru dat