Commitment and corporate goals

I am reading a book about influence.  I am enjoying it a lot and will write more thoroughly later, but I was struck by this.  I often wonder why employees are asked to set yearly goals.  So much can happen between January and December it seems meaningless.  I think one reason might be that, by putting a commitment in writing, people are more inclined to meet that commitment.  If the goals we employees write on these wretched forms are at all beneficial to the organization, then the organization might benefit from having us write them.