Perhaps because virtue signalling has never been more popular?
In an industry where we all earn well, have similar qualities of life, similar careers, etc. virtue signalling (often wherever possible) appears to have become the perceived fertile soil for differentiating yourself, and "elevating" yourself.
I mean, when the President broadcasts to the world that transgender people can no longer serve in the U.S. armed forces, it only deepens the systemic bias. Why is it then selfish to showcase that they are able to write good books too?
Because diversity of thought is important. You're missing a lot if you only read books by people with similar views and experiences. For example, if you're a white man and you ask all your white male friends for book recommendations, you're going to end up with a pretty homogeneous list.
And why would the people making this list have to provide that diversity? Either they want to on their own, without anyone telling them, or the reader of the list can go looking for it themselves. Note, I'm in favor of all kinds of diversity, but I disagree when people start telling other (groups of) people what they should do.
In an industry where we all earn well, have similar qualities of life, similar careers, etc. virtue signalling (often wherever possible) appears to have become the perceived fertile soil for differentiating yourself, and "elevating" yourself.