The simple and basic reason is that there is far more volume with reddit and the 5000+ readers than here which has the same ~30 people posting.
"5000+ readers"
...with a collective IQ that doesn't reach that same number.

"~30 people posting"
...which often means that there's actual intelligence being expressed and the multitude of
readers get their answers before having to post.
https://bitcointalk.org/index.php?action=stats ...
and the idiots think twice before posting crap.