I do not know where you have dived and what dive guides you have had, but I feel truly sorry if this is your impression!
Actually I stopped doing guided dives about a decade ago (because I do love sea horses, frog fishes and the such
). The pitiful impression I got from looking around at what goes in and out of the water around me, hearing comments from friends on both sides (guided dives consumers and dive guides...), and from diving here and there during the last 20 something years or so.
Good luck for you that you've found a good dive operator, that fits you like a glove to your hand. It looks to me that you are some sort of "local diver" that feels at home with your diveop, and apparently comes there frequently. This is not the case for many tourists that come only once in a few years to the area, and maybe will never come back (bad diveop?), or perhaps only return in a couple of years before they choose another dive destination in some other place of the world. This divers may be satisfied with slightly lower degree of acquaintance with your precious dive sites, they may contend to dive 45-50 minutes and "see as many dive sites as possible"- after all- they may never return here and need to put a "v" in their logbook...
Think about it!
A dive guide who after every dive can't wait to get out of the water, or is QUOTE "on a hurry to get out" shouldn't really be a dive guide, should he?
You could be wrong about this one.
Some guides get paid per dive- if you keep him 100minutes in the water, he could be losing money because of divers with good air consumption (but he must keep nice maybe you tip him for his good patience- maybe not). And then, suppose he got another 5 divers with air consumption worst than you (maybe they are inexperienced? eh?)- how will he keep them safe while you want to extend the time until you get your 50 bars? What about you? Can you dive calmly knowing there is a whole group of wet divers are counting the seconds for you to get out of the water?
The same nice guide may have another 5-6 dives scheduled for the day, he doesn't want to spend 80 minutes on a single dive.