Bill,
A+ on that. It apparently started with a few M1911 types who seemed to be competing to see who changed recoil springs the most often. I think the winner was some guy who said he changed his every 100 (yes, that's right, one hundred) rounds. Absurd, unless he worked for Wolff.
They say springs don't last. If that is true, they are inferior springs, because good ones last and last. Want an example? The valve springs in your car operate thousands of times a minute. How often do you change them? How often does the owners manual say to change them? They are made to last the life of the car, and will still be good when the car is scrapped.
Jim