Because it's a tiresome, tropey, and ultimately invalid complaint. Look downthread at the person who said the FreeBSD commit log was better than this page, despite being inscrutable to security practitioners who don't work in the kernel and not saying a word about proven exploit vectors.
These complaints aren't about what's better or worse for the user community; they're about people trying to put vulnerability researchers in their place.
It's not even a complete description of the vulnerability. It's what the kernel maintainers need to know to understand and fix the bug in the code. The claim that it's superior to the branded vulnerability page gives away the whole game.
As a member of the user community, I only care when it appears on the security list and then that it's patched. And I want to see that on the changelog. And that's about it.
I don't want or need fanfare, marketing or any of that stuff.
It's a bug for fucks sake. There will be people having web pages for Gnome user interface bugs next.
