All your example are in the Apple ecosystem. Depending on where the author is from, it may not be that surprising that they wouldn't know about them. In my corner of the wolrd, Apple was basically non-existent until the iPod and iPhone.
Fortunately my little isolated island chain [1] in the South Pacific Ocean was one of the places where there was someone who brought in early Commodore, Tandy, and Apple machines only a couple of years after the USA and by 1979 or 1980 there were stores in my nearest 40,000 pop provincial city that stocked and repaired them. My school got an Apple ][+ right at the end of 1980, just as I graduated, but the Math HoD [2] asked me to take it home for some of the holidays before I started university and figure it out and come and explain it to him.
A few months after I got my first job after university I persuaded my boss to get the new Apple LaserWriter (in fact the demo unit from the launch), which I connected to the company's Data General "mainframe" (MV10000) and programmed in raw Postscript. In 1987, when the Mac got good enough (e.g. Mac II) we got on those those too as it was just sooo much better than a PC/AT.
[1] NZ
[2] who died just over two years ago, aged 99 1/2, we'd kept in touch the intervening 40+ years
In most corners of the world, actually. Apple was reasonably popular in the US, the UK and a few developed countries (think marketshare of 5% in 1999) and basically non existant everywhere else.
