Random word lists are quite a lot harder to type than sensible text.
I'm grateful to have learned to touch type in high school, even though I resented it at the time -- it seemed like it was being presented as a stereotypically feminine skill, so of course I balked. I learned on an electric typewriter, not a computer keyboard, and every time I'd get fast enough to earn an A on the exercises the teacher would bump the threshold up by another five words per minute. I didn't feel like I was very good. I was sneakily glad that the typewriter I was using had a correction ribbon in it -- most of them had been removed, because we were supposed to be learning accuracy (a typo was a 5-wpm penalty). These days, I can feel myself make a typo, erase the typo, and retype correctly without any hesitation.