Actually, its more than that.
The reason why the food pyramid reccommended so much carbs and starches is because it was a subsidy to farmers yo clear out all of that excess grain, snd soybean(mostly oil) was because they were super cheap alternatives.
Hell, the "low fat" craze in the 80's and into the 90's? Food manufacturers were taking the fat out of food, yet replacing it with sugar to cover it up because "studies" pushed said it was fat making everybody fat(which we know is bullshit by today's studies) and thankfully the whole seed oil being healthier for us is taking the same turn, but the whole " all saturated fats are bad" myth clings on.