The theory that gay people in the United States enjoy living on this tips of peninsulas, which is quite possibly a subconscious phallic desire. For proof, look at three different cities: San Francisco, Provincetown, and Key West. All three are known for high percentages of gay residents, thriving gay tourism, and prominent gay pride parades; and all three are located at the tips of peninsulas.
Granted, Key West is technically part of an archipelago and not a peninsula, but US Route 1 connects the entire island chain to the mainland, so for practical intents and purposes, the keys form a peninsula.
No doubt uptight ignorant people will cry "homophobia" when they read this, but there is nothing offensive about gay peninsula theory.