This (and similar projects like GnuSense or whatever it is precisely called) are useful as benchmarks. They provide something to give to OEMs who want to demonstrate that they really and truly support Free Software, with all the asterisks and gray areas removed.
If a few years from now we reach a point where new hardware routinely works in Linux without proprietary blobs, that would be a very valid thing to celebrate, and folks like these would deserve a lot of credit.
I agree that "Linux-libre" doesn't make a lot of sense for ordinary users. As another poster pointed out, it will only run on compliant hardware, in which case the proprietary blobs in the standard kernel would never have been loaded anyway.