Because whenever you look at any book or site to choose a given name from, it's usually divided in half: names for boys, and names for girls. They might have a section for gender neutral names, but it will only have a dozen names in it. Like it's only an afterthought. This gives the impression that that's all there is to choose from. It gives the message that virtually everyone must fit into a clearly-defined box of masculine or feminine.

Because some nonbinary people prefer to choose names that seem neither masculine nor feminine. We need to know that our options are more than to either choose from only a dozen neutral names, or use a name that makes our gender expression seem to align with a masculinity or femininity that may not suit us.

Because women notice just a bit less gender-based job discrimination when they apply for jobs under a gender neutral name, and in other professional communications. This can help narrow the gap in male-dominated fields.

Because transgender people have to deal with just a bit less risk and difficulty during their transition if they were given gender neutral names when they were born. Then they can take their time choosing a feminine or masculine name, if they prefer to do so.

Because I think parents will be more likely to give their children gender neutral names if they can easily find enough such names to choose from. I think that could help parents feel accepting of children who turn out gender nonconforming or transgender.

Because it matters to break up the gender binary in society. Given names are one of the places where we can see assumptions about the gender binary engrained in society and in personal presentation.