As near as I can tell, 'traditional' modern Mexican food uses habaneros very sparingly - their spiciness seems to need to be very diluted within that culture. Logically, if it was always thus, people would breed their habaneros to be less spicy. Was Mesoamerican food once much spicier? Were habaneros so difficult to grow that it was worth diluting them and risking over spicing food simply to save land? Is the capsaicin content necessary to grow them effectively? What explains this?