I agree.
Divemasters in training are required to lead some dives as part of that training. When I have supervised such dives, I have timed them, and they never go faster than 10 FPM. I am sure the ascents on every recreational dive I have done with a DM leading it are in that ballpark. Fortunately, in recreational diving, there is no harm in that, and it is better than an ascent that is too fast.
In technical diving, it matters. When you are doing a decompression dive, taking longer than the planned ascent time adds to your decompression time. If you are using a computer, it does not matter, because the computer will add that time automatically, and the only issue you will have is wondering why your actual dive was so much longer than what you had planned.
If, on the other hand, you are not using a computer, it can make a critical difference. I had two friends who got mildly bent after such a dive. One of them had used a computer in gauge mode as a bottom timer, and that allowed them to scan their actual dive profile. They had planned the dive as a certain amount of time at bottom depth followed by a planned series of stops on ascent. Their review of the computer showed that they had ascended to that first stop very, very slowly, in effect adding to the bottom time without compensating for it in the decompression stops.
