Pure speculation: random, untrained and disinterested parties might be better than CIA analysts at making geopolitical predictions because their results aren't politicized. "Are there WMDs in Iraq?"
A lot of these federal positions are military. So I assumed it was some enlisted guy out of high school that didn't want a desk job but wants to be firing guns. He's been doing it years and wants out. He's not invested in any of this analysis.
Compared to the guy that self-selected to sign up for an analysis website as a hobby. He finds it fun to think and analyze. He gets points for being right and has a score to improve.
The other factor is workloads. If a CIA analyst has to make X decisions in Y time, then they may be rushing.
I read this story as a failure of federal services to reward successful performers and remove failing performers.
The more involved you are, and especially the more accountable you are held for your decisions, the more you're likely to second guess yourself. There's normally a reason your second guess wasn't your first guess.