Why have zoning if people can ignore it?

Re “SD pushes shortterm rental rules in era of virus” (July 8): When buying a house to use as a vacation rental, short-term vacation rental owners knew they would be operating a business in a residential zone.

What is the purpose of zoning if the city ignores zoning laws? If the number of vacation rentals is reduced, will there be a lottery? Why can’t the existing law be enforced? It wouldn’t require a vote, compromise, placating the unions or the cost of collecting fees. I would like my neighborhood back. Virginia Hatt San Diego