Why do you think polyunsaturated fats are bad for you? What does it do to you mechanistically? And where did you learn this from? Also isn’t it a bit hyperbolic to call it poison? It doesn’t literally kill you. I’m sure you would choose to drink a glass of seed oil before you had a teaspoon of cyanide.
Discussion
PUFA are fragile oils that become toxic as they break down. In the production of seed oils, they are absolutely shredded. Not to mention the extreme imbalance caused by consuming unnaturally high amounts that would be impossible to achieve without heavy industrial processing.