That's exactly the point of any and all home security techniques. If a burglar is determined enough to break into YOUR house, he's going to be able to do it no matter what you do. Luckily, most burglars aren't picky, and they'll just choose the house that's the least amount of work. Putting things in place that will slow a burglar down increase the likelihood that the burglar will give up and move on to an easier target.
That was my understanding as well. It is meant to slow down and frustrate a would be burgler. 3M recommends a burgler alarm be installed as well. If an alarm is sounding and the burgler is struggling to get through the glass it is likely they won't stick around long. 3M is sending me samples in the mail. If I decide to do this it will be professionally done.