Smart people are capable of doing some very dumb things! Volkswagen is the latest example.
For the past decade, automobile manufacturers have been hustling to satisfy increasingly tough emission standards set by various countries. California has been setting the pace over the years with the U.S. EPA not been far behind. Through new technologies related to catalytic converters and computer controlled fuel mixtures, the automobile manufacturers have generally been able to meet these new regulations, except for diesel engines where the technical challenges have been huge.