It obviously was a figure of speech though, not literally. In fact, there might be way more than a million people that look down at the shifter when they reverse, but it's hard to prove given I doubt there was a survey done on this.
"a million people" is a commonly used phrase, here's an example from Grammarly that explains how the phrase "a million people" is used generally:
"Have you ever heard someone use the word “literally” and thought, “They can’t really mean
literally.” There were not
literally a million people at the concert. That final exam did not
literally kill them."
Simile vs. Metaphor: What’s the Difference?
I actually got that habit of looking down at the shift to confirm the position when shifting in reverse from when I learned driving and it carried over to my usage of the stalk. When I change between drive and reverse, I look at the stalk due to habit. I generally don't do that however when I am activating or deactivating AP, for that I treat it naturally like the turn signal, where I don't actually look at it.
As a sanity check, I tried to think what kind of videos would people shift into reverse and the first thought is driver test videos. And the first result I found that they had a camera on both the driver and the shifter, sure enough the person looked down at the shifter to reverse (around 3:30):
Here's the second result (1:20 in), and driver looked down:
And the third (3:51 in driver looked down to shift into drive, 4:30 a different driver looked down to shift to reverse):
I'm not going to bother going further down the list, but from the results I think the people who DON'T look down at the shifter when switching between drive and reverse is probably the unusual ones!