This is an interesting question from different views - the consumer, the user, and the provider. What should be noted is the term 'severe' and how that is interpreted. Oil change intervals become a generalized view instead of a specific. 'Severe' usually appears with the manufacturer recommendation(s) in the manual. Many times the word 'depending.' At least from my experience.
Example A: Drive from Hemet Ca to San Diego CA to go to work or 83.3 miles or 1.5 hours one way. Add the return trip and you have approx. 170 miles and 3 hours at what 60+mph. x 5 days per week. (I guarantee you he drives at 80mph and just never gets caught :)
Example B: Drive from Elsinore Ca to Orange county to work. Drive distance approx 46 miles maybe 1 hour. Yet, it is a hilly drive and the motor cycles through various levels of strain, shifting etc going up and down hills. Again multiply by 5
Example C: Drive from one side of town to work on the other side of town or 3 miles, through city streets never exceeding 40 mph. x 5
These are true examples: The driver in A changes his oil every 3 mths because he is old school and today his motor has 240k+ without major repairs.
Driver B is not old school and has had the motor replaced once, and no documentation to intervals of oil change service
Driver C is old school but changes oil to mfg specs at 7500 (I know it is me).
A secret to some and not to all is that it is just as important to change the 'oil filter.' Then the question becomes do you filter old oil through the new filter? Does the cost of oil come into play.
The myth is the truth you speak, it is the advancement of technology with lubricants, filtration and engine design.
An interesting article to read may be found here http://www.dtsc.ca.gov/TechnologyDevelopment/OPPTD...
But, I ask, how many of the millions of average drivers, take the time to discover. The automobile is the second largest investment of the average consumer. Should they protect that investment? With maintenance? Or do a risk evaluation?