Immature or not???

My cousin is having a baby shower and I'm planning it and setting everything up. Also getting things together like food and what not. She decides to tell me that she wants to give tickets out to people who brought gifts and they have to show the ticket in order to receive a plate! If they don't have their ticket or can't show proof that they brought a gift they don't eat. I find it distasteful and sickening especially when their will probably be plenty of left over food anyway. Why not feed everyone?!??? Is that immature or a good idea??