This is a learning process for me to figure out the intended implication of this story and to maybe pass it on to others once I reach a conclusion that I am satisfied with. The basic premise is not an assertion, it is an assumption.
The tower of Babel story is a myth, a just-so story. It has the scientific accuracy of attributing lightning to the anger of gods and disease to evil humours. It is based on earlier Babylonian myths.
Or do I really have to explain that people can, in fact, be mulilingual, speaking a variant of their mother language in their profession that is unintelligible to those not initiated in the profession?
I do not see the relevance of this. Language diversification occurs among populations, not small groups, unless those groups become isolated from the larger groups. One of the best examples of a profession speaking a different language would be Catholic priests, who are all expected to speak Latin. There has been no linguistic speciation attributed to this.
Or maybe we can actually discuss the Tower of Babel and chew through whether my assumption pans out or listen to an alternative explanation that goes beyond the literal interpretion?
The prehistoric California region is a classic example of linguistic differentiation. At contact, between 80 and 90 different languages were spoken within what is now California. These belonged to as many as 20 major language families, with at least seven of those language families entirely unrelated to one another (see Golla 2011).
Time depths exceed 12,000 years based on archaeological data (and there is no evidence of a large-scale flood within that time).
What we can take from this is that the Babel story is a myth and does not account for the evidence provided by either linguistics or archaeology. There is no reason other than religious belief to take it seriously.
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.
Belief gets in the way of learning--Robert A. Heinlein
How can I possibly put a new idea into your heads, if I do not first remove your delusions?--Robert A. Heinlein
It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers