Bang on Bri.
Believe me, I also have big opinions about some of the placings, and would argue till the cows come home, against their ranking. My no.1 is actually about 48 (Tralee) and I've played 9 out the top 10 and and 16 out the top 20. For me there are courses not in the top 100 that IMHO should be and same the other way around. I'd be interested to see how many differences between their list of 12 years ago and now.
I liked Trump, very photogenic, but I'm a sucker for views. Others may prefer a bigger challenge, and so on.
What I would say from being on the other side of the fence is that GM have a good "process", A minimum of 3 reviews for every course, and with at least 35 other contenders outside the current list, so not a closed shop. By admission, I dont know other magazine's process to compare against, and would be interested to know.
However, I would be surprised if there were less than 65-70 courses that are in the same lists across most other lists also, so would then lead me to think that whilst not definitive, but if say 4 lists have a similar 70 courses that there is a consensus.
I certainly wouldnt be calling people "idiots" as the OP has done though, especially without knowing at least some of the processes.
I think the moderation of findings goes a long way to creating a list that is at least 80% accurate to within a few places for each course. In that respect, the glass is 3/4 full.