Zoning Laws: Do They Really Matter?

I would like to take a minute to talk to about ZONING. My understanding of the purpose of zoning laws is based on the following information:

Theoretically, the primary purpose of zoning is to segregate uses that are thought to be incompatible. In practice, zoning is used to prevent new development from interfering with existing residents or businesses and to preserve the "character" of a community. Zoning is commonly controlled by local governments such as counties or municipalities, though the nature of the zoning regime may be determined or limited by state or national planning authorities or through enabling legislation.

Most zoning systems have a procedure for granting variances (exceptions to the zoning rules), usually because of some perceived hardship caused by the particular nature of the property in question.

A special use permit is a term which allows a specific exception to the zoning regulations from a list of acceptable exceptions for a particular parcel of land in a district of a particular zoning character. The local zoning authority reviews and grants special use permits.

So, sounds good, right? Zoning laws properly applied should prevent INCOMPATIBLE land uses. 

For example, a crematory is INCOMPATIBLE with residential and school properties, for a number of reasons. Not the least of which should be property values. 

Since in 1995 Lilburn did NOT have any allowance for crematories, this use should have required a Special Use Permit - because it was NOT an allowed use. Law allows for non-conforming uses to be grandfathered in ONLY if it was an allowable use at the time it began, not the other way around. 

Most importantly, the community's right to comment on a special variance that was being considered was completely BYPASSED and the crematory was allowed to begin without the public's knowledge and continues with NO SIGN or Listing to indicate that it is there.

So my question is: Does zoning in Lilburn mean anything at all?