The real answer is timing. The Crown swears. The Crown does not swear a lot. Why? Because the timing is bad. If Warrel said "fuck" every other line, then the songs would blow goats instead of ruling. Let's suppose that he said "maple leaves" instead of fuck. It would have the same effect. It would sound shitty, pointless, and random.
Take a lesson Alexi Laiho.
Well, he doesn't do it often, and it doesn't glaringly stand out as much as explain the emotion felt behind the particular moment. Which is appropriate timing. *shrugs and farts at the same time for effect*
Create the Infinite
"Listen and I'll tell you the story of our end
Equate the calculation, salvation's fucking dead". not that it matters. i'm just pointing it out for hell of it.