Wow! Some discussions are like Lazarus. "Just when you think it's safe to go out at night", etc.
Okay, my two cents.
I think the key has been mentioned by Pete (Guido Bros.) and it is integrity. If the original measurer states that there have been no changes to the course I believe that we should be able to renew the course forever. If the original measurer is no longer involved, I would accept a single ride by an experienced measurer for renewal (assuming that the ride shows the course to be at least the advertised distance ... if it doesn't, a second ride would be required).
Fortunately, this does not yet seem to be a big problem in NC. So far this year I have certified 52 courses (well ahead of last year which set an all time record) and not one of them is a re-measurement of an expired course.
My biggest argument against the new policy is on calibration courses. Usually a calibration course is used multiple times by the original measurer during the course of a year (unlike a race course which is used once and usually not observed by the original measurer) and he/she would be immediately aware of any changes in the course. That being the case, why does it have to be re-measured after ten years?
As I recall, in the original discussion concerning this at an RRTC Annual Meeting, the main reason given for the change was basically mis-use of the renewal process by many people. Pete Riegel related that many times he would get a renewal request that swore that the start & finish nails were still in place and that there were no changes to the course but the person requesting the renewal did not even have the original certificate/map in hand when making these statements. Consequently, they may or may not even know what the original marks/route were. IF that is the main reason we did away with renewals, it could be fixed by requiring the original measurer be the only one who could request a renewal.
The argument that many (or even most) courses have road changes during ten years may or may not be true, but even if it is true, why should courses which DO NOT have changes be required to re-measure?
As a state certifier and vice chair, renewals are/were a pain in the butt; however, I am still in favor of them under controlled circumstances.