[mejohnsn]

You ask, "why would you put extra layers on it, which will have to be unwrapped to get to the inner logic?".

There are two possible reasons:

1) you know your audience is not that logical to begin with, and need to be lured by illogical appeals to emotions etc.

2) you know they could be persuaded by logical argument, but need help summoning up the will to persist in following it. In that case, you mix logic with entertainment and exhortation. But you must mix carefully, to keep from falling into the trap of merely luring by illogical appeals (or even seeming to do this). Unfortunately, few have the patience for this, so many take the easy way, (merely luring).

Plato took course 2) often in his dialogs. Augustine did the same in both sermons and treatises. Aristotle never did, at least not in his surviving works (his dialogs are lost).