I don't think Titanfalls Extraction cancellation is an indictment on the genre because the future of the genre isn't "Extraction Shooter", it's "Extraction".
No genre in gaming can pull a wider variety of players under one roof than this one. That gives it a massive market advantage.
Bungie bungled this genre to epic proportions because they made a broad genre Extraction Shooter in the most narrow way possible. Marathon seems to be taylor made for "arena shooter bro". It's possible the Titanfall Extraction game was headed for the same fate as Marathon and Respawn pulled the plug.
I would have said you were crazy two weeks ago for saying this. I don't think you're crazy today. Marathon strikes me as a high risk, low ceiling type game.