I agree that a specific date by itself is somewhat arbitrary, but knowing whether the rigging has been replaced one year ago or five years ago definitely plays into deciding whether it's time for a change. And for me, being able to find a scrap of paper with the date of my last shroud change four or five years from now is not very likely. Factor multiple boats into it and forget it. So having the info right on the shroud would be helpful for me. It's just like the oil change alalogy- if I didn't put a little mileage reminder on my windshield, I'd never change the oil.
sm