Eh, that is one explanation, but pigs are only slightly worse than other domestic animals, which also have parasites and whose meat would spoil. The other and I think more likely explanation is formalizing differences between themselves from other ethnic groups in the region and making that division explicit. The early precursors to Israelites and Judeans were inland in the hills and shepherds, and were defining themselves against the more urban and coastal Philistines and other Phoenecian peoples. Pigs are preferred by more dense populations since they can be kept in a pen and don’t have to move around to graze, and the coastal element is why there is also prohibitions against shellfish.