One thing that stood out to me was when Zurvan was relevant. Here in NA/EU all we had was "skip soar or disband", with a single tank and 5 dps (most of the time unable to skip soar btw, but that's another matter entirely). Few reasons why this was done, largely in part due to laziness. Why learn the mechanic when you can skip/cheese it? All it ended up doing was causing drama and people to run around like idiots if they didn't skip, because players on our servers are completely incapable of adjusting on the fly.

Meanwhile over in JP, they were farming it in raid finder, which forces a 2/2/4 composition and doesn't guarantee a soar skip, they just shut up and did the mechanic, got the kill, happy days.

We're just lazy over here and want the path of least resistance, instant gratification, selfish, whatever you want to call it. That's why there's such a discrepancy in raid clears every tier.