Part of the "excess cones" issue is that we need to separate adjacent course elements from each other. It's a small site, and to get a course more of more than 20 seconds without resorting to keeping things painfully tight, you have to get creative with the space. To keep people from "jumping lanes" so to speak, we have to put a "wall" of cones between them.
Aside from that... when there are 50,000 cones out there at our disposal, and you send people out to set up a course (even if you give them a map showing exact cone placement), many of them tend to take it upon themselves to add more cones. Since most course designers don't want to place EVERY cone on the course or pick out every other cone when folks get over-zealous, we often let it go and just look at what's important.
What's important? 1. That the course is easily followed (this one was), 2. That the proper line through the course doesn't instigate a high cone count from small mistakes (cutting an apex too tight shouldn't result in more than one cone down), 3. That the areas we expect "off course excursions" will not result in high cone counts OR safety problems (usually means making the course wide enough that most spins hit NO cones).