Because I don't use mind control. Nowhere. Not ever, not one. My capital has a society level of 178. And is doing just fine. I don't get all the blabla about having to put in MC at 80. I don't and I'm thriving.
Well, you don't, so feel free to seek consumer goods, but for those nations that do?
As for capping at 80, looking at the graphs, I don't see why. 85-90 seems like a better place to cap it at.