Why do some people working in stores (claire's accessory shop did this for example), why do they believe that if they just out right pressure you to buy something that it will work

I went in there to see if they had hello kitty purses, they had one plain white one which was really really bland , and boring, mainly just white, and no fun colors on it, so i decided to leave, this sales person stops me and says can i help you find something, so i asked if that was the only hello kitty purse, unfortunately it was, and i hated it, so i said ok thanks and then she actually had the audacity to preach to me about how it is trendy and therefore it is worth buying, even though i find it repulsive, crazy. it was extremely over priced for such a plain and boring one also. If your going to try to pressure someone to buy something that they have absolutely no intention of buying and hate at least make a more convincing argument than it's trendy, which is kind of insulting to think that u are going to buy anything that is trendy. Yes they have to make a living by selling stuff, but the question here, is why in such a dumb and insulting way.