The answers to your questions are answered in the summary in part, and in the article in full. Perhaps you could try reading either or both?
Anyway, he's a tech writer, so I assume it would be easier for him to call up Adobe and say, "Hey, I'm working on this hilarious project, do you happen to have..." This probably would not work for you and me. Plus, he's not a FOSS luddite, he has written several articles on using old software. The first paragraph of one about DOS:
Every now and then a new piece of hardware, or software, is released that causes me to pause and think, "Why, on Earth, do we update our tech so often? What, exactly, can I do with the latest stuff that wasn’t possible with the previous version?"
So that should answer that question.