Why don't girls message first on Tinder?

I just don't understand. Sometimes they even say in their bio that they won't message you first. Yeah, they get 10x as many likes and messages as guys do, but that to me seems like more of a reason to message the ones you're interested in. Part of me just feels like it's a vain attempt at feeling good about themselves. It's really insulting for us to match and then not message/ignore mine.
Why don't girls message first on Tinder?
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