When there are water/moisture issues in crawl space or basement, frequently there are microbial issues. Sometimes "Testing" for microbial activity is a prudent strategy. There are benefits to perform mold testing because IF you have a mold problem you can focus your efforts to the correct scale and correct location thus limiting costs.
Unfortunately today there is no shortage of so called "Mold Experts" that have had a weekend "Mold" class and are now "Certified". Often times poorly trained and inexperienced "experts" simply guess as to the quantity & type of mold. "Guessing" in the mold remediation business can have far reaching and potentially life threatening consequences. There is no substitute for an Accurate Laboratory Mold Analysis. Having accurate information can be very useful for medical professionals should their services be needed.