Some languages diversify due to technical jargon used by specialists.
I think that the tower is a metaphor for diversity within the culture arising through class rankings.
As with any building project, we have the labourer who has a specific skillset and unique terminology for tools and techniques. Such as "gypsum" or "gypsumboard" is jargon for what the layman might call "drywall".
Then you have "greenboard" which is drywall used for damp applications, whereas, again, the layman might request "mold-resistent drywall."
The point being that many languages or sublanguages, "slang' exist within a building project. The foremen, of course, must be familiar with all these languages and have another language all their own.
What we see is a division of work and hence, a division of classes and cultural identity.