Soil Scientists do a lot more than delineate septic drainfields. Soil Scientists help regulators in interpretation of Soil Surveys such as planners so more intelligent land planning decisions can be made. Poor interpretation of  surveys has and will cause poor planning decisions and road construction, for example. Soil Scientists assist realtors and developers to create proper road networks.  

Interpretation of soil testing and soil surveys would have prevented much of the disasters surrounding the Mountain Valley pipeline.  a proper soil survey was not required for that project

Arlington County has experienced many failures of the infiltration trenches and rain gardens. They have subsequently made Soil Scientists involvement in these projects mandatory.

These are a few instances of why deregulation does not make sense.