My point is, at the very least, it can attract an audience outside that bubble.
Anecdotally, I know a number of friends who bought an Xbox 360 for Blue Dragon, Lost Odyssey, Ninja Gaiden 2, etc. but didn't care about what one would call the main pillars of the Xbox brand. I myself jumped into the Xbox ecosystem for Sega's Xbox exclusives; Jet Set Radio Future, Gunvalkyriem and Shenmue 2 were my first Xbox games (admittedly JSRF and Sega GT were bundled).
I mean, I'm with you on some of that, but those games also came out a long time ago. The video game landscape overall is so drastically different now you can't really compare it like that. These types of games just aren't getting made with same frequency anywhere.
It's less about the portfolio than this being a continuation of MS mismanaging their projects. Phantom Dust, Recore, Scalebound, Fable Legends (which killed Lionhead), and now with Crackdown 3 being MIA for a long ass time there is cause for concern about the direction there.
Maybe it's less them "mismanaging" and more a purposeful change in direction?