Well, you got me there.
When the CoP first came out in 2002-2003 their first shot at scoring jumps was approximately this. The easiest triple jump was arbitrarily pegged at 4.0, then it went up through 0.5 increments for Salchow (4.5), Loop (5.0), Flip (5.5) and Lutz (6.0), with double Axel at 3.5. Each extra revolution approximately tripled the score. (So a double toe would be about 1.3 and a quad toe around 12.*
Over the years they tweaked the relative values (bringing the toe and Sal closer together and also the loop and the flip), but the main thing was that when skaters started doing multiple quads, the ISU had to back off from the "multiply by 3" rule of thumb because this put the value of quads through the roof and obliterated the contributions of anything else. (GOEs were a little stingier, too.)
For spins, I think that the ISU faced a quandary. Just "doing a spin" (or a spiral) without reference to quality was not much to score. They came up with "levels" which rewarded contortionist changes of positions, etc., but I don't think they ever achieved a point system for non-jump elements that they are truly satisfied with. Many skaters (Michelle Kwan was one) lacked the flexibility to do the highest level spins, so they tried to compensate by accepting lower levels but making up for it by concentrating of quality as reflected in the GOEs. But it never worked out to the skater's favor to sacrifice base value or levels for quality. This fact was welcomed by the "it's a sport" fans, but not by everyone.
Although the ISU has acknowledged the dilemma and has chipped away around the edges (for instance by making GOEs a percentage of base value in recent revisions and by restricting repeated quads), I believe that the problem has never been seriously addressed. Quadruple jumps count so much more than anything else that there is no (competitive) reason for a skater to do anything more that just rotate in the air as many times as he can in 4 minutes. If you waste your time on anything else, well, you are just wasting your time.
Some people are happy with this. "It's a sport" and the name of the sport is "rotating many times in the air while being weighted down by ice skates on your feet." Fans who hope for more come smack up against the question that you ask: how should the the scoring go if we wanted good spins, for instance, to be scored higher than bad ones, with enough of a scoring gap to make a difference. If I knew, I would run for ISU president.
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* By the way, when they did test scoring of old programs with the CoP, they found that quads were so over-valued that Timothy Goebel won the 2002 Olympics ahead of Yagudin and Plushenko. Points, schmoints, this was clearly wrong, so they hastily reduced the relative value of quads even before the first actual IJS competition.