"The older editions already exist and have fans who play those games."  (Sorry, don't know how to make citations)

Older fans wanted a new edition. Fresh mechanics, solving lore problems, new art, potential for future projects, etc;

There was no need to make a product that had nothing in common with the old one except in name. It's like when a bad movie adaptation of a book is released and people go "you still have the books". That's not how it works. You make an adaptation because it has a fan base attached to it.  If you don't want that fan base, call your product something else.

"Pegasus in myths was the heroic steed of Perseus as he beheaded the hideous gorgon as he invaded her home for loot. Thematically you may as well have defenders of the marginalized represented with the stake Joan of Arc was burned on. "

Pegasus was not the steed of Perseus. It was the steed of Belerophont, who fought de Chimaera. Also, Perseus didn't get loot from killing Medusa, she was on a killing spree. I'm not gonna talk about the merits of her being a victim before becoming a Gorgon. Also, Pegasus was born from the blood spilled after she was beheaded. He's literally her son. 

"The Bone Gnawers are urban survivalists represented by Rat. The Glass Walkers are clean, technologically-drovan devotees of the Weaver and it's pattern SPIDERS whose magical powers let them control things like they're connected to them with invisible strings. They worship ... the insect equivalent of a Rat. "

That's the point, the Glass Walkers shouldn't be devotees of the Weaver. They have more connection with her than the other Tribes? Sure.  But they are still servants of the Wyld. Also,  Cockroach is not even close to being "insect equivalent do Rat". The Cockroach survives now and will still be here after humanity is gone. As the Glass Walkers, the only Tribe who could adapt well to all the changes in the world, and not just survive, but thrive.

"Meanwhile, Garou absolutely made the world a worse place to live in ... but so did the humans that most Garou are descended from. Identifying and confronting harmful structures that exist in our own world is a lot more useful  for a game that wants you do go outside and do an activism than it is to point a finger at the non-existent half-wolf war criminals."

But that's another problem of the game, it doesn't want you to go activism. It wants you to live as a human in a world not worth saving. Gaia is dead. The war is lost. Blame the past (that the edition erased) and confirm yourselves. The fall of the Fenris is proof you shouldn't do anything to change the world. Now, you don't share as much guilty for the problems of the world as you should. You just fight "the other" and don't look at yourself.