Post-Snowden, I think you will find there are more who care about this than there were in the past. The only reason any of us take this seriously is because of what we factually know about government agencies snooping on us.

Problem is that bunch of nerds (myself included) is not viable market. PSP / ME it's just one of problems on hardware layer: almost every single device have closed source firmware or microcode inside drivers and there no device on motherboard that have DMA and can be trusted. Hardware manufacturing is hard and even if some company would be able to produce viable hardware there just not enough customers who going to pay 10-20 times of price premium just for security.

And even if you can mitigate hardware issues your "secure" system will be practically useless because on software layer best you can get it's PoC like CubesOS since desktop Linux is just damn insecure.

So if you want solution that actually let you have work done then you have to sacrifice something: keep important data on isolated always offline PC, get older hardware without PSP / ME (or deactivated one) for online and pray. Then always put newer untrusted hardware behind hardware firewall / VPN / etc.

In the end several completely isolated devices for different use cases give you much better practical security than one backdoor-free PC / server.