Anti-missle systems on comercial planes?

FedEx launched the first test flight of the Northrop Grumman's Guardian anti-missile system on a comercial MD-10 cargo airplaine. The antimissle system is adopted from military technology and the anti-missle system directs a lazer to the head of an oncoming missle which then disrupts the missles guidance systems. This technolgy will cost arount 1 million dollars to buy for each aircraft and $365 of maintenance per flight. (Information taken from CNN.com)

I think that this is a good advancement and use of technology, however I do not know if it is necessary for all comercial aircrafts to be equiped with this system. There has only been one incident in 2002 where terrorists fired missles at an Israeli jet and missed. I do not know if it is worth spending so much money on this system seeing as it has not been a large problem in the past; but it is always better to be prepared in order for the chance that this system may save human lives.