Wow, do you have any any pictures? How close are any that bloom well? How big of a neighborhood? For a city-wide anomaly, I would look at environmental causes: reduced sunlight due to Canadian fires for example, a deer population explosion, uncommon weather that caused bud set to occur significantly earlier than normal (and thus, the buds got removed when late winter/early spring pruning occurred, improper pruning, temperatures high enough to promote a summer dormancy period, some type of new disease, etc.
