That guy was a piker. The computing power of a typical smartphone is several orders of magnitude greater than that 360. The palm pilot used a Motorola processer derived from the 68000 that powered the early Macintosh. I had no trouble learning assembly language for that platform, just as I had no trouble with the Mac, because the register layout and orthogonal instruction set were analogous to the 360, which I had learned as a teenager. The 360-on-wrist point was passed at least 20 years ago.
No, he just wasn't as prescient as he could have been.
I heard the story when I was in school in the late 1970s.