.....I'm sure you can find lots of people who say their fins are the best and there are many different styles. If you pay attention while on dive boats you will likely find many instructors and dive masters wearing the Jet Fins. Probably for the same reasons that I do.
Different types of diving, different conditions, different dive boats, different fins.
Warm water tropical boat diving in Florida and the Caribbean, I see many dive masters using full foot fins. Diving in the quarry at Dutch Springs Pennsylvania, Jet Fins everywhere.
Like you say, different styles.