Gene, I definitely plan to do that, even for courses I measured gratis in the past and will do so again. But my point is I have race directors saying, "So what if the certification has expired? The course is still accurate, and that's all 99% of the runners care about." You're right that it's a small expense over 10 years but most race directors look at the here & now and when the cost of timing, shirts, cops, etc. are all going up saving a couple hundred bucks by foregoing a recertification seems like a good move, even if it is penny wise and pound foolish.
In terms of insurance, it's possible to have an event sanctioned without the course being certified (or vice versa, thankfully) unless it's a USATF championship.