Agreed, firmware security by chip manufacturers has been underwhelming to say the least and we can blame them for that. But in this specific instance I still don’t see the benefit of a fix for consumer usage. Companies have a responsibility and accountability toward their users, so a fix is due, for personal laptops/PCs the threat is toward the owners themselves (activists, diplomats, journalists, etc.). The latter do not buy second hand equipment, and if the firmware is compromised while they own it, they are already in danger.
I’m not saying this is a small issue and nothing should be done. I just noted that the issue is not as big as some other hardware-based vulnerabilities we encountered in the past. And every threat model calls for a corresponding counter-measure.