A big reason we hate to be ignored is because of our Ni. Ni allows us to come to conclusions about things without having to jump through hoops, particulary when it comes to dealing with people. Despite all of this, Ni is rather intangiable, and even a primary user will feel at dis-ease if they are forced to use Ni and not back it up. So when people ignore us, they aren't confirming the feelings that Ni gave us. We are sort of left in a state of limbo with things, and then our Ni runs away further and can lead to racing unplesent thoughts.
If someone gives us even just a little attention and or feed back, our Ni is confirmed and we feel at ease.