Mold testing is not always a waste of time. If the client has Allergy or Health Issues, their Allergist may want to know what genus and species of mold are growing in the home. If you are doing commercial inspections then they will definitly want to know what genus and/or species they are dealing with for reasons too many to list here.

If no one has initially tested then the Remediator may test to see what they are dealing with for removal.

I totally agree that the source of the water intrusion must first be corrected, then the mold removed.