The POH usually has the answers.
The C172 I occasionally fly specifies 60-70 for final approach.
I agree about the epidemic of too high speeds. Every instructor seems to want the speed they were taught, plus a couple of knots for insurance.
Locally, they use 70 knots for the approach speed, which is (just) within the Cessna recommendations. But, they then apply the MOS tolerances which are +5,-0 which means if you go any further into the book range you are outside tolerances. It's OK to be above the book range by up to 5 knots though.
I have noticed that many aircraft are much easier to land when flown at the book speeds. Maybe those factory test pilots know something after all. Easier landings might save a few students some dollars on circuits too.