Parents why don't you let your kids have a pet of believe they will take care of it (brutally honest answers)?

My late mom never believed us when we said we'll clean up after it. She still didn't believe us. She said no everytime we ask. She said they're messy, a huge responsibility and we weren't ready. She said, "I don't believe you. Most kids end up forgetting and the parents take care of it and sometimes die. Frankly kids aren't the best when it comes to taking care of a pet." It sting when she said she didn't believe us but she didn't care. My mom was very strict. We didn't have our first pet until I was 15.