I think it's down to decades butter-fear, a scrape of the stuff would stop your heart dead. Doctors would stand around your corpse, shaking their heads. Butter, they'd mutter.
I'm pretty sure we ate Stork margerine as students, which was rendered fish bits, hydrogenated into a mess of trans-saturated fats that sailed somewhere between sarin and plutonium in the toxicology stakes. You really should have had to cross the street to avoid a tub of that. But then we used to live off a diet of microwaved kebabs from the Diamond Frozen Food store around the corner. Oh the smell of microwaving doner kebab meat. A friend of mine had a skunk die in his car's a/c system, that's the only similar smell I recall. He had to write off that car.
Nowadays margarine seams the province of 'healthy' olive oil spreads and the like. Who needs olive oil spread? Get a baguette, tear a chunk off, soak it in olive oil. Eat that and drink the rest of the bottle. Job done.