For you sure they are a celebration, but they're still different and a wedding is much more than a celebration. You gave the example that your friends are going to your birthday and you're not expecting a gift, well it's a poor example, because at weddings it is expected you will get a gift. Unless you specify otherwise, you know you will get something! To even say you aren't expecting it is moot, people give gifts at weddings and we all know that! To call people names for having wishing wells or registries or anything is just mean, it serves no purpose.