I often see “whingeing,” too.
I’ve seen it explained on the Guardian UK website, and it was indeed as mentioned above. NASA is Nasa on their site b/c it’s said as a word would be, rather than spelled out, like the ISS. Visiting/living at a large number of UK news sites and forums encouraged me to give up on the periods between acronyms’ letters, like U.S.A. as you’d mentioned. It makes writing and typing them much easier.
Few UK businesses use an apostrophe. I got great catalogues for years from a UK saddlery company called Robinsons. One of my favorite US saddlery catalogues during jr high and high school came from Miller’s in New York.
