Oh dear, they cannot be serious......
While a good "apprentice" airline pilot will probably do much to prove the concept a theoretically sound one, a not so good apprentice could quite literally spell disaster.
A very wise man once said there is no substitute for experience. It is still true. At best good training can only hope to equal good experience. In the practical world of course, it very often falls quite short. And with accountants running the company and the company paying the sim. bills, well that's a fertile field for the roots of disaster.
IMHO the guy in the right hand seat may be bright and quick, but if things go suddenly pear-shaped, and he hasn't got prior experience to fall back on, you could effectively be back to single crew. And I am not talking about the standard engine fire/depressurisation/engine failure/smoke-in-the-cabin type ICAO disasters that happen once in a blue moon (he has probably been well trained in sim for that stuff), I am talking about the more frequent average shi*ty day that unfortunately just seems to happen in aviation. The sort of multiple-factor scenarios that quite often don't involve any aircraft malfunction, but conspire to make the job just that much harder anyway. The things you learn from those days cannot be taught in sim, they can only be experienced in the practical environment of line flying. They are certainly much better learnt in small aeroplanes where the public is not as much at risk.
Can anyone seriously suggest LESS experience in the cockpit will actually DECREASE the number accidents and incidents attributed to pilot error? Surely less experience in an effoh requires more experience in the Captain to make the system work. So what happened to CRM ? I distinctly remember something about an ideal experience "gradient" on the flight deck, and it certainly DIDN'T involve a near zero-hour effoh. Is it responsible for a company to expect a captain to compromise his skills as manager to take on the extra burden of also being an instructor (from 1+1=3 to 1+1=1).
I am already flying with effohs who, despite being good for their experience, could really benefit from some basic single pilot stuff. It is not their fault they are getting jobs flying airliners with only 250hrs, yet can't get from point A to point B without radar vectors, or the FMS. It is not their fault they are not quite sure how to break off an instrument approach for a visual one when they suddenly become visual on the outbound leg of a procedure. It is one of those things that is hardly ever taught in the sim., yet it is basic and important for a safe approach and landing and should be second nature. What else would be missing in a zero-hour effoh ?
If you are having one of "those" days it is invaluable to be able to fall back on practical experience. If the effoh has very little experience, the more chance there is that things could happen that he is unprepared for. In a busy cockpit where an economy of words is essential, the captain may not have time to fully explain what he is doing and why he is doing it (or what he wants to see done). If the effoh is flying it, it may even mean the captain has to take over. Not an ideal situation I think. Let us not forget that people also make mistakes. Surely in this scenario the system would be a great deal less tolerant of either flight crew erring, but especially the captain.
It seems to me once again commercial pressures are eroding away the often subtle and intangible safety factor that a good experienced crew provides. It is a complete nonsense to suggest it cannot significantly compromise safety.