I basically know only check dives from egypt (no experience with liveaboard though).
First dive is a "welcome dive" at the house reef. So you dive with a guide and have to briefly show the basic skills. Clear half full mask. Clear emtpy mask. Regulator change to secondary. And of course a weight chdck. Then its a normal dive.
No experience with "advanced certifications". But from experience that is something ok. There are just lots of divers who dive very rarely and only on vacation...
Keeping that in mind I can understand this.
*edit* I have read here somewhere about judging how quick someone descents as a measure for the ability. Maybe I got that wrong, but if you are going for as little lead as possible to be as balanced as possible, you are descending slow. If you just sink fast, you are likely having too much lead.
Now that in combination with an inflsted BCD/Wing, maybe from check and/or to have plenty buyoncy to float, it just takes a couple of seconds to descent. Thats especially true for the first meter to break surface tension. So I do not think its an appropriate measure to judge a divers capability.
If you are talking about someone who descends, then go up again due to breathing pattern thats a completely different story.