My guess is that guyharrisonphoto has adopted an ascent strategy that involves a serious of stops. A lot of us do this, and regard them as more or less mandatory -- mandatory in the sense that they WILL be done if they can be done, and would only be blown off if there were an extremely exigent reason for doing so (managing unconscious diver, for example).
Rock bottom IS conservative in some ways, but not in others. The assumptions about gas consumption can be way too optimistic, depending on who your buddy is. I have dived with novice divers whose unstressed SAC rate is about what my rock bottom calculations assume is stressed gas consumption. I'm quite sure my rock bottom would not suffice to rescue those folks, if they were at all frightened. Luckily, the dives I do with such divers are generally done with just plain silly amounts of reserve gas (me, an HP130, and a 60 foot max depth) so I don't have to worry about it.
I think the single biggest lesson from going through the gas management stuff is that it takes a lot more gas to get two people to the surface in an emergency than you think. And not all out of gas situations are the fault of sloppy diving (although many are). Freeflows and clogged dip tubes can ruin the day of even the most responsible diver.