I would rather think it was about idolatry/other gods. Boiling a kid in its mother's milk sounds like a ritual, symbolic act of cruelty - pretty tame by Levantine standards, with its brazen bulls and child sacrifices.

If you believed the gods were sadistic bastards, whose power you could call on with an act of cruelty - it wouldn't be such a strange thing to believe, after a rough period of hundreds of years where cruel people rewarded again and again - then a little symbolic cruelty to whet Baal's appetite might seem like a clever move.

This is what I have heard as well. However, imagine the gastrointestinal distress one would have after consuming spoiled milk and not so fresh meat...