Why do people ignore registries??

Hope this does not come off as ungrateful. I truly am appreciative of all friends and family who have been kind enough to gift anything for the baby. However, the amount of non-registry gifts we have gotten is appalling. I’m completely ok if somebody gets something extra that they thought was cute or fun for the baby. Some people think the products they used for their babies are the only way to go though. We recently got a baby gift from a friend who had their first baby recently and multiple things as I opened them they said “I saw you registered for X, but this is so much better so I got you this instead!” Or before buying a gift, some have asked “do you have X product yet?” And it’s something I don’t want to use for baby, but they insist it’s a “must have”. I appreciate when people give me recommendations based on their experience as parents, but there are very different parenting styles that you can take that would impact whether or not I want some of these products. I wouldn’t even mind so much if a gift receipt were included so I could exchange. I put a lot of time into our registry…just not understanding people who can’t realize that a registry is quite literally exactly what I was hoping to receive.