Well, a lot of it has to do with how you want to do the dive, and what you are willing to do for preparation. Diving the Doria, from the stuff I've read, was always a gamble against changing weather conditions, so one of the biggest safeties, caching bottles, may not have been very possible. I don't know -- I've never dived the Doria, and don't even want to.
I do know that a team of divers I know personally dove on, and did documentation of the wreck of the Atlanta, which lies in over 300 feet of water. And knowing the people, I also know that gas was planned so that each diver carried enough, or had easy access to enough bailout (since they were on RB80s) to get to the next gas supply. I'm also quite sure the logistics were frightful and a lot of preparation diving was done, and safety divers were on site. This is quite different from the person who gets on a charter boat and decides to do a 200 foot dive with the guy on the opposite side of the aisle, where days (or more) of preparation hasn't taken place, and there's no guarantee that the two people have calculated safety reserves in the same way -- they may not even be on the same gas!
You can do major, deep, challenging wreck diving in a way that manages safety reserves and allows team members to help each other. You can also do it with each diver planning and understanding that he's on his own and has to get himself out of whatever trouble he gets himself into, and that seems to be the way Mr. Chatterton developed his deep dives. But I think saying that you HAVE to dive that way because it isn't possible to do the dives any other way may apply to some exploration diving into very small, silty cave passages, and perhaps some artifact diving where you KNOW you are going to blow the viz. But it doesn't apply to the vast majority of cave or wreck diving.
"Sometimes, when your world is going sideways, the second best thing to everything working out right, is knowing you are loved..." ljjames