I am not sure if this is a complaint against Honda, or outboards in general?
Also you don't say what size you want--but from 150 to 200 hp would seem to be logical for 6 to 7 people on a C Dory 25.
All outboards can have failures--as can any engine. I have heard of every brand failing at one time or another--sometimes after only a few hours.
I would doubt that twins, even if 90's would have enough power on a C Dory 25 to "save the day"--and have the speed to get to, and keep up with whales, in a Whale Watching Commercial boat.
Unfortunately there are not many used motors in this HP range, and if if they have been rebuilt--they are suspect. I would much rather buy a new engine, than a used, or rebuilt if my lifely hood depended on it.
C Dories have been used for Commerical fishing in AK for many years--and I suspect in many other areas. There have been C Dories used for Diving, law enforcement, and research commercial uses that I personally have seen.