It is exactly a “false sene of security”.
A nation state adversary can remotely hack Qubes installed on an ordinary computer, even if it has no preexisting compromises.
But someone reading the warning would assume they are not compromised as long as their hardware was pristine before installing Qubes.
I have a feeling we’ve been through this before. This post by @Sven pretty much describes the way to go.
A nation state adversary can remotely hack Qubes installed on an ordinary computer, even if it has no preexisting compromises.
This is an oversimplification, a blanket statement which CANNOT be true. By the same measure, a nation state adversary can kill you if they really wish to, see the nuclear physicists of Iran, killed in Iran.
I give you that, if you run QubesOS on a machine with a vulnerable ME, you may be vulnerable to a magic packet attack. Yet none of the disassembled BIOS dumps revealed any occurrence of such code, and I will qualify this statement with “at least in Lenovo’s BIOSes”. There exist vulnerabilities caused by stupidity, like using that free TCP/IP stack from the '90, which everybody used and didn’t care to check. But there are moderately easy ways around this too, from “never connect WiFi” to “always connect through a firewall chain which drops illegal TCP packets” and “never use IP-in-IP or other stupid Cisco hacks”.
In conclusion, I perceive the Qubes warning as fair. Qubes cannot stop you from using “password1” as your disk encryption password either, and this is a greater risk than ME.
This is a technical forum and such statements without any technical details do not belong here.
I tried to say the same thing, with more words and a softer delivery… 
How do you know that?
Then that person would have poor reading comprehension, as the warning does not say that at all. The warning makes no guarantees about what Qubes OS can or will do. It only points out a limitation of Qubes OS.
Here again is the warning text:
Warning: Qubes has no control over what happens on your computer before you install it. No software can provide security if it is installed on compromised hardware. Do not install Qubes on a computer you don’t trust. See installation security for more information.
Please point out the part that is misleading or incorrect.
(tried to delete my reply, but couldn’t see how)
Technically it is perfectly correct. However, I don’t think I’m the only one who would read into this that Qubes will provide protection from hardware being compromised, especially remotely.
I really do think a target person could be endangered by a false sense of security. I was not trying to nitpick or be condescending.
Based on experiences I am not comfortable discussing.
Obviously, I cannot expect anyone to believe me based on such a statement.
Okay, I understand. If you have some better language in mind or would like to propose an amendment to the existing wording, please have a look here:
The documentation is a collaborative volunteer effort, and all positive contributions from the community are welcome! 