It's probably about power. Certs control is getting higher value, so control over this policy means more negotiation power with whatever states (governments) need from platforms.
It's easy to imagine something like: "give us some grant taxpayers money and we'll add your cert to our trusted list/remove theirs cert/disable cert when run on this hardware/etc."
It's easy to imagine something like: "give us some grant taxpayers money and we'll add your cert to our trusted list/remove theirs cert/disable cert when run on this hardware/etc."