"On top of it, there tends to be many of the same topics posted by the same folks over there as over here so things get redundant."
And on controversial topics, it's important to have diversity of opinion. That drives lots of posts 
. No diversity of opinion leads to relatively boring conversations amongst those who want their own opinions reinforced. Tribalism at its best. Anyhow, at this point we mostly know each other's opinions, so there may be less debate at present.
