If you had the chance to make a supplier who creates millions of chromebooks happy, wouldn't you take every opportunity to help them, especially if it costs you little to no money at all. Obviously there is a big reason why they don't want this backdoor removed.
Basically he says that even Google is puny (in terms of production units) in front of Intel or Samsung, and cannot ask for custom firmwares.
Hardware security is currently a shit show because of global monopolies/"oligopolies".
They operate a top 3 cloud service and have enormous internal data centers as well.
Maybe if Lenovo, Toshiba, Acer, Dell, etc all asked Intel to provide said blobs (and the threat was tangible) then they would probably reconsider.