There are those that pooh-poo the creation of lists that reflect an average opinion of variously qualified "Raters" to create "Rankings". Golf Digest has been infamous for starting that process with their "200 Toughest Courses" (based upon Rating & Slope) which morphed into Golf Digest's Top 100 USA - America's Oldest Ranking or something like that - massaged by "Tradition" among other things.
For those that do not think that rankings are taken seriously, I'll save 1000 words now...
Case Closed. But, remember "Tradition".
BTW, Eugene does not scare my top 100. The trees are majestic and don't intrude on turf nor play as much as one might suspect, but the course is far too ordinary. It just happens to have a long history with the USGA.