Lots of ways to look at it. The engine is probably redlined at 10k rpm? So, the bike would be running over 120mph at 10k if it had the hp to run that fast. These engines can handle the rpm. If it was geared higher, it wouldn't have as much acceleration in top gear. My ZN700 is indicating 5k rpm at an indicated 75mph, probably less than 70mph actually. Redline is 10k. For cruising on the interstate, the engine sounds busy, but it can take it. I suppose you have the option of changing sprockets to lower the rpm. My ZN700 is shaft drive so I don't really have that option.
1985 Kawasaki ZN700 Shaft, 4cyl
1989 Yamaha Venture Royale
2007 Yamaha Royal Star Venture