While the gist of the consensus is correct, I would like to raise a point:
Namely, that Gary in fact had a point. I am sure, the "company man" in him took that point and overstated it, for the reasons that were mentioned. The point I speak of:
OD&D is very, very, very free in many, many things. So free that it lead to incompatible gaming groups and quickly to RQ, Traveller or Tunnels & Trolls. With AD&D, the baseline was much stronger so that a straight line can be traced from 77 to the release of 3e.
OR, said differently: only via AD&D was it even thinkable to write computer games. For OD&D, the moment people wrote computer programs for it, they drifted the rules and gave life to new rulessets.
Also, the freedom of OD&D truly relied on ressourceful DMs that basically had to be wargamers or worldbuilders of such genius, that one can barely speak of a product. It was more like an inspirational tool for the gifted. We can see this very clearly by the failings of many OSR-disciples. Reductionism is strong in many of them, because they otherwise do not seem to be able to understand it. Also, all too many view it through the lenses of Basic D&D and AD&D or even 3rd Edition.
So, AD&D as a product as a structured set of ideas is much, much, much more stable than Arnesionian D&D ever could be. For better or worse.