I was writing a similar comment to yours, thinking about "value to society", and value to loved ones, even negative value of enemies. I agree that talking about "value of humans" is not very useful.

Then I realized that on an individual level, everybody is infinitely valuable to themselves. You are your whole universe. From that perspective, I agree with the author that "Humans are valuable."

We have laws keeping humans alive and safe because we are valuable in that sense.

I don't agree that we need to go out of our way to preserve human art though, or their thoughts on the value of "creative artifacts". People will make art if they enjoy making it. Whether or not other people appreciate that art is irrelevant.