Hi FireShock,
Most Schools expect you to be able to write a decently-organized essay in a short period of time (which shows your ability to communicate effectively with written words). As long as you score at least a 4.0 on the AWA, then you should be fine at most Programs (and a 4.0 out of 6.0 is a relatively easy score to achieve). Business Schools are also allowed to read your AWA prompt - they will sometimes use that prompt as a reference point for any Essays/Personal Statements that come with your application (since some applicants hire writers to create their essays for them, your AWA can be used as a way to verify that academic fraud is not taking place). Beyond that, if you 'skip' the essay (re: leave it blank) and a School notices that, then you will have effectively told that School that you chose not to complete the Full GMAT - and I don't know too many Admissions Officers who'd be interested in accepting someone who won't do the work that everyone else did or refuses to train for what is ultimately a fairly standard component of the Test. This is all meant to say that writing the AWA is not that difficult, nor does it require a lot of effort to do properly. The overall benefits of writing the essay far outweigh the minor benefit of skipping over it.
GMAT assassins aren't born, they're made,
Rich