[ghaff]

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.