The issue is not widely known, silicon is very costly to manufacture, and most people frankly don't care, as long that spying is unobtrusive (and hell it is so).
Also, most people already are living with the thought that their computers are cracked/hacked/virused the moment they are connected to the internet - all my friends and relatives ask me to check their computer for viruses - almost none trust their computers or phones (especially Android phones, it seems). For such people, where this is the natural state of the world, it's very hard to imagine that they can change anything about it - and telling them that there are backdoors from the moment the laptop is assembled, doesn't help much.
Sure, but the silicon & libre drivers already exist and don't need to be manufactured, so at this point its a marketing problem of selling a more secure computing box.
Anyone trusting a computer - any computer - is a giant fool in my book. Trust is a strong word, and computers suck balls fundamentally at keeping information safe.
Also, most people already are living with the thought that their computers are cracked/hacked/virused the moment they are connected to the internet - all my friends and relatives ask me to check their computer for viruses - almost none trust their computers or phones (especially Android phones, it seems). For such people, where this is the natural state of the world, it's very hard to imagine that they can change anything about it - and telling them that there are backdoors from the moment the laptop is assembled, doesn't help much.