As a course designer, let me add a few thoughts.
I can't speak for others but I have no clue what I am doing.
You start with a rough idea of what would be good and show up with a few teammates and start putting the thing together. It's a pretty big job and it's generally cold so only a few guys are doing the work. Not many want to leave a warm bed to show up and build a race course. I always feel sorry for the Turin guys because Montrose is always absolutely freezing. It soon gets to the point where the sun is going down and you just want to be done. This is if you're lucky enough to be able to set up the night before. Most times you're doing it race morning and are freaking out that you won't finish in time. Many decisions are made "on the fly" after brief conference. It's imperfect to be sure. With any luck there's time to ride the course you've designed before the first race. I think I did this once.
This year cross has exploded. Each race has done over 300 and I think last week they did 388. Lansing last year we did 180, and we were very happy for it.
So now what? We gotta come up with a course that can handle the new crowds and make for a challenging race. My own thought is it should be spectator friendly too, so throw that in the pile too. It's very difficult. Where but experience are you supposed to learn this stuff?
SCW is lucky this year because we've got all Friday to set up the course and may have practice runs available to all racers Friday afternoon. We'll have a chance to tweak and improve. We've got more time when time isn't always an option.
cross your fingers