I just made myself chuckle by wondering if anyone ever pronounced IBM as “ibbum” or something.
A funny, now largely obsolete acronym, is SCSI: only noobs pronounce it “ess see ess eye”. Likely apocryphally, some people early on suggested pronouncing it “sexy”. But the pronunciation that stuck, not only in English but also in many other languages, was “scuzzy”.
Well done for teaching the world the “correct” way to pronounce an acronym. lol.
Acronyms are, by their very definition, a contraction of a description into its initial letters to avoid tediously speaking out the entire description ; there is no “correct” way to pronounce them, they aren’t meant to be pronounced. To say what you’ve said is to say “that’s the incorrect pronunciation of that slang” - in essence, it’s a matter of choice whether one creates a phonetic analogue of said acronym so it rolls of the tongue more easily, or whether they formally say “Ess See Ess Eye” <—— (phonetically worded for clarity).
One might even say that formally pronounced, letter by letter, is more correct than the “slang” equivalent of forming these contractions back into words, since there’s only marketing people who sometimes create pronounced acronyms for the same reason anyone else does; to make them memorable (and profitable, in their particular case.)
“NICAM” is an example of this, but even then, that doesn’t mean it’s “right”, and that any other spoken version of “NICAM” letter by letter is, therefore, “wrong”, it’s just what happened to stick.