While I'm personally not a fan of gamepass fear mongering, I also find it a bit weird that so many people blindly believe MS's PR during the first few years of a really long term strategy.
No corporation cares wether gaming develops according to the best experience for the user, but solely on how they can make the biggest buck out of it. Google MS, Sony, you name it.
If Gamepass gets big enough that devs depend on it, there is a valid concern that MS will adapt policies that are detrimental to certain game styles.
I mean, pretty much. It's really not 'fear mongering,' especially since we now actively know Microsoft was doing exactly what Google is trying to do now in the beginning. They changed course, and are tailoring how they work with devs for them for now, but this isn't really about Stadia or Game Pass specifically, as much as it's the possibility of what these services could lead to. That should be the takeaway from all of this. But people can't get off their shill shack for a second to see that, and instead we get people pre-emptily defending a service before anyone even brings it up because the connection between the two is that obvious.