[Shades]

I think the F word is so unwanted because of the not only the subject matter, but the fact that "ck" makes a somewhat verbally explosive, opening it up for a more extreme sound. That's why it can be more offensive than, "I want to rape you", when in reality, isn't as severe.

Same with "the other poop" word, it's more verbally distinct, which makes using it with "You're full of" more offensive than "poop", when it means the same thing.