Because you are not on the same wave as they are at this point in time.. Everyone views things differently usually based on how they were raised and what kinds of things they have experienced.. Everyone experiences different things differently so there for can feel different about things.. It also depends on their path and the things they are suppose to experience.. Everyone has a different path and will experience different things based on that path.. This effects how people view things.. Sometimes something disrupts the path though and can make them experience things they were not intended to experience and can through things off balance causing different effects and distortion of views can be one of them effects..
I too often have this same question in my mind… Even though i pretty much understand the answer.. I still have a problem accepting it and often become frustrated that some people are the way they are..