When you remove fat from food it becomes unpalatable unless.... you add sugar. Thus the increase in added sugar in just about everything which has helped to contribute to the rise of obesity and metabolic syndrome and all the diseases that come with it from diabetes to fatty livers, heart disease, etc.
So who's to "blame"?
The government in some ways, even though they seemingly meant well when recommending low fat diets (they're just now beginning to recommend reduced sugar and ease up on fat warnings).
Food companies in some ways who seem to have known about sugar's addictive properties and engineered their food to keep you coming back for more rather than keeping you healthy .
Consumers in some ways for not reading labels, exercising more, reducing portions, etc. But who could blame you when the government and the food companies were trying to convince you that what you were eating was good for you? (unless you had time to dive into the research yourself but let's face it, that's not an option for 99% of people)
One of the best explanations I've read of not just why sugar (fructose to be specific) is bad for you (in the quantities Americans but also most of the world eats it at) is the book "Fat Chance" by Robert Lustig . You can also get a glimpse into his arguments via his youtube lectures .