When answering this question, you can talk about the emotional and psychological reasons behind this reaction. Some people might feel ignored or unimportant if they don’t get a reply, which can lead to frustration or anger. It can also be about expectations—nowadays, people are used to quick responses because of instant messaging, so when someone doesn’t reply, it can feel disrespectful or even hurtful. You can also mention that it depends on the relationship between the people involved; for example, if it’s a close friend or family member, people might take it more personally.