Nonsense. Training is whats at issue, not gear.
A trained diver knows how to manage an OOA diver, even a panicked one.
A trained diver knows how to return both to the ascent line and has no issue going side by side with an OOA diver on their octo.
A trained diver knows how to manage a safety stop, even with another diver on their octo.
And you are right DIR or not is not the issue, training is.
It's true that with proper training all that is possible with a short hose octo. But with a long hose all that is possible and is a lot easier, especially if the OOA diver is less than perfectly trained. That's important as "less than perfectly trained" and "OOA" are often co-occurring events.
All divers, regardless of their gear configuration and regardless of how well trained, will react differently (than they were trained) when suddenly faced with being OOA. And that gap between their training and their reaction will widen the longer they are OOA.
I know how to drive and I know how to ride a horse and both will get me across the state, but it's a lot easier and faster in a car.
This is hardly a reasonable analogy. It's more like the difference between a coupe and a sedan.
I don't understnad why there is so much resistance to a long hose. .... with enough training....
The resistance comes from the notion foisted upon recreational divers that if you are not using a long hose you are somehow an unsafe, untrained and somewhat of an uninformed diver.
The long hose has a specific purpose, to allow divers to share air in a confined space. Can it be safely used in recreational, open water dives? Sure.
Is it unsafe to do so? Nope.
Will it allow for a safer air sharing event is open water? Nope.
Does it require significant training to use? Nope, just a little practice.
Will it get tangled up in the Kelp and I die? Nope.
A standard recreational octo configuration also has a specific purpose. To allow the safe sharing of air in a non-confined space.
Can it be safely used in recreational, open water dives? Sure.
Is it unsafe to do so? Nope.
Will it allow for a safer air sharing event is open water? Nope.
Does it require significant training to use? Nope, just a little practice.
Will it get tangled up in the Kelp and I die? Nope.
If you are my dive buddy, I frankly could care less what your gear configuration is but I do care if you know how to use it and I know what to expect from you should a situation arise.
If an advance in equipment and configuration makes dealing with an emergency easier, why not use it?
Good question and one that a few have a very difficult time answering with anything other than, it's another failure point or it's entanglement hazard or you don't need it, just take a class.