You make popcorn sound like stuff.
It's practically impossible to eat anything today that is healthy aside from fruits and vegetables.
It isn't like it's the kind of food that will kill you the second you eat it and like it's all we ever eat.
Almost nothing will kill you in small doses, poison for example, requires a certain amount to be lethal. It just so happens that the chemical diacetyl is a poison and is in your microwave popcorn.
As for the fat content, well that has never caused anyone to drop dead in an instant, it takes a couple of years:
A medium-size buttered popcorn, the report said, contains more fat than a breakfast of bacon and eggs, a Big Mac and fries and a steak dinner combined.
People that eat like that are not known for living very long.