Not sure. There's GNU after all. Wikipedia's "arbitrary" standard is actually pretty common in my experience. But I'm not sure I could come up with a coherent explanation as to why.
GNU is an acronym, that's fine. But if they insist on Nvidia, they should also insist on Xkcd (it's not an acronym, just an unpronounceable artificial word).
And radar is an acronym too and it's not commonly capitalized although SCSI is. And, often, Fortran, not FORTRAN. I'm not making a case for how things should be. I'm just observing how they commonly are in style guides, etc.
I think part of it is a general stylistic distaste for having "unnecessary" caps. See also general shift away from "Open Source," "Big Data," and the like.