"Fuck it" is the most powerful and subsequently destructive phrase in the English language, allowing one to ignore consequence in favor of pure action, with the tactic acceptance that you've likely released forces far beyond your control.
For a phrase with so much destructive potential, it's interesting to note that the root of the phrase goes back to sex, the act of creation, and even possibly love. Sex is the effort to produce a child, a force which will, whether you like it or not, grow beyond your control.
"Kill it" doesn't have the oomph. Why not, when it essentially speaks to the same destructive dynamic and disregard of consequence?
Because "kill it" invokes death, which is to put to rest. "Fuck it" invokes life, which is to spark chaos.
