To quote from the article:
"If you have a software nasty on your computer with admin rights, it's already a game-over situation"
Depending on the malware, you need to (do whatever) to remove the 'software nasty', so not quite game over. But:
"with the ability to write to and bury itself in your motherboard firmware via this left-open mode, the malware could ensure it survives a drive wipe or change, and evades detection from antivirus tools"
So why this conclusion in the final paragraph?
"exploiting this bug would require the aggressor to have local admin-level access to the machine, and if a miscreant is running privileged code on your PC, there are about a thousand other things you'll want to worry about before considering the integrity of your mobo firmware"
With the 'bug' fixed, your PC has a big problem; without it your PC (mobo anyway) is a piece of scrap. This is a serious, and simple to fix (?), problem. No excuses required