Languages develop too quickly to be traced that far. Even if there was a protolanguage (there could have been one in Africa I guess) by the time continents were explored, the languages would have no relation to any "ur-language".

True, mostly.

The point with Protong, however, is that there was a globally-spanning civilization which did not have the latency we commonly associate with early human development. The language was supposedly spoken globally by a world-spanning human civilization which was destroyed by the cataclysm, requiring us all to re-develop ourselves.

Like I said, Szukalski was a kook. But contrasting his findings with more scientifically appropriate methods, is certainly of great interest to those of us following along...