A ha! I knew if I dug around enough I would find an answer to why garlic was not deified in the past (as I initially believed). The information came from the book “Da Vinci’s Kitchen: The Secret History of Italian Cuisine” by Dave Dewitt.
Back in the day (the day being any time between the height of the Roman Empire to the time of the Renaissance), there was this belief system of hierarchal links, from which one could map base elements all the way up to God. In between was found the entirety of the world, with each animal, vegetable, mineral and all things divine given a certain status. The Divine was given the highest status, while mineral, not having a spirit, let alone a growth cycle or an appetite, was given the lowest status.
Within each of those divisions, further rankings were made, based off of their relation to the chain. Items that stayed closer to the earth (root vegetables, shellfish) were seen as “less divine” than items that were closer to God. Birds who could fly were seen as a noble food, while ducks and geese (who tended to hang out in the water) were seen as “less noble”. Fruits that grew high in the trees were viewed in a better light than the vegetables that grew closer to (and often in) the ground. As you can imagine, these rankings affected the choices that some made when eating. Garlic and Onions (and later potatoes) were seen in the same light then as we see Wonder Bread and Velveeta Cheese sandwiches today – They were eaten if that was all that was available, but a person’s status would be better determined if their diet consisted of grapes, pigeons and spices (which were somehow excluded from this chain due to their exotic status and the cost associated with their procurement).
So why was garlic looked down upon? Because it was a food that didn’t bring a person closer to divinity. Thus it became prevalent within the diet of the lower classes, which in turn further alienated it from those with the power to influence.
The above should be read as a rough generalization of the process as a whole, as there were undoubtedly nuances and exceptions that I (and others) have yet to discover. But as a guideline into European food anthropology, it’s a great starting point.