We're once again in an era of mass politics. The world is now too chaotic and painful to think about for most, so people outsource freewill and critical thinking to thought leaders.
On this very website you can see examples of this from both sides of the aisle. Leftists can no longer process reality without a series of filters, cultural references, media talking points, helpfully supplied phony statistics, you name it. On the right, people go to /pol/ and take the weak path and start miming conspiracies and low effort memes/greentexts.
It's not stupidity so much as weakness, though there's a strong correlation between the two