Private septic systems design is a very complex subject, typically due to the varying soil characteristics and depth. Being below ground fits in the category of “out of sight out of mind” until septic effluent surfaces or backs up into the house. Systems that worked fine for 20 years for an older couple can fail in a few months when a young couple with children move in. The amount of water each family uses varies considerably. Simply having a garbage disposal may require pumping the septic tank twice as often due to the addition amount of solids and grease flushed down the drain.
IMO I think anyone buying a house should be required to take some basic training on septic operation and maintenance. But that would toss a turd in the punch bowl for realtors and building contractors.
Preventing ground water contamination is the primary reason septic system regulations exist.
Also it would be a good idea to mention the different types of systems, and that home owners need to be aware of what type of sytem they have and how to maintain it.