Because it is rational to reject potentially introducing allergen exposure to populations with no acquired tolerance.

Lobsters are crustacean, not insects. Shrimps and roolly pollies too. It's a nice fact to tell in your next cocktail.

Funny enough, lobster was basically the cup-of-soup of early colonial days.

https://www.history.com/articles/a-taste-of-lobster-history

Yet don’t eat the shells.