Fear is the easiest, simplest, most visceral way to get people to do something. Scare them half to death and they’ll be much more likely to do what you want.
It’s one of the easiest to take advantage of people.
In the era of the 30 second tv spot, 140 characters, 24/7 news cycle and short attention spans, fear is the quickest way to get attention and break through the noise.
The downside is that people get scared and paranoid, think things are worse than they are, and that otherwise decent people are evil and are out to get them. That threats are bigger than they really are.
It leads to polarized politics with no room for grey area, nuance, other peoples opinions. We need to fight its advance.