You presumably believe that science alone can explain reality. And that's fine. But many people don't, and I'm not just talking about the traditionally religious.

Scientifically, the "love" we have for our children is simply a genetically-programmed strategy for best ensuring that our genes are passed to future generations. It has no meaning.

In fact, scientifically, nothing has any meaning. Whether we live or die makes no difference at all, and when someone kills another, the only reason it's "wrong" is because society is trying to preserve itself so that individuals can pass on their genes to the next generation.

Again, if you're OK with this, that's fine. I'm not going to try to make you change your mind. But hopefully you can understand why others, many others, inform their view of reality with sources other than science.