The 16T front sprocket on the 750 was a disaster because of its high-speed capability. That sprocket has maintained that reputation ever since. Honda went up to 17T and then 18T on the 750 to greatly reduce the wear on the chain, so the legend tends to follow that path.
That said: the real chain-killer on the 750 was: chain technology at the time of the bike's introduction. This part of the legend doesn't stay with the popular facts, though. When the chains got better, thanks to the ones Bill mentioned above (Diamond XD or XDL being the longest-lasting of that breed) and the RK copies of it, the 16T front sprocket wasn't then such a bike-killer. BUT...it will make for pretty high RPM when running at hiway speeds on a 550, for sure. This change was sometimes made for in-city bikes (like in Chicago, New York, St. Louis in my old stomping grounds) that never seemed to see the freeway, which tended to make them foul the sparkplugs. Lower front gearing was a 'quick-fix' and improved on the acceleration in those cases.
P.S.: the Diamond XDL is still the ONLY chain that I run on my own 750. I'm on the 3rd one, now, at [beyond] 151k miles. Nothing lasts like them.