You have no hope of influencing a large company through channels like this one. You are talking with a low-level person who has no authority to change anything, and whose job is only to try to convince you to accept what Intel is doing.
What you got is therefore only the statement Intel uses to justify not cooperating with us.
It could be that the Coreboot developers can find statements which are misleading or false, and publish an article which would put pressure on Intel.
Some of the points are simply distractions or illogical. For instance:
BIOS is a part of the reliability and performance promise of the hardware.
Is that true? If so, so what? That is no reason not to let us run our own BIOS.
Chipset specifications at the level being discussed are commonly considered proprietary by all silicon vendors, not just Intel.
In other words, "Everyone spits on your freedom". Even if it were true, so what?
However, it is false: some computer models do work with free BIOS. Intel compares badly with them. This is one of the statements that maybe could be criticized in a published response.
The open source firmware work that Intel *is* sponsoring could lead to a solution where proprietary low-level chipset initialization code from silicon vendors is made compatible with open source higher-level platform initialization and pre-boot management.
As they say, this is not a complete free BIOS, just part of one.
If the "proprietary low-level chipset initialization code" is in ROM on the chips that it initializes, then it is tolerable. (It might as well be circuits on that chip.) Otherwise, it is insufficient unless made complete.