I really don't think it's just a legend. The linked article and Wikipedia (https://en.wikipedia.org/wiki/Segmented_sleep) give enough evidence that it seems unlikely to be a complete myth.
And saying "I hate waking up in the middle of the night" doesn't really have much to do with this. If you consistently slept for 12 hours a night, you might find it a lot easier and more pleasant to get up in the middle, and that's exactly what one of the studies in the Wikipedia article showed.
And as anecdotal evidence, even a few people in this 2-hours-old comment section say they've tried it with good results.
I fell into this routine for a few weeks during my OS course in college. Didn't have much social life as I was working on my OS for about 10 hours each day (or catching up in my other classes...), so it was easy. I went to bed when I felt tired, usually around 8 or 9 PM, woke up for an hour or two around 1 or 2 AM, then fell back asleep until morning, 7 or 8 AM.
During the middle hour, I felt the intense relaxation and started writing poetry/drawing during the period. I'd often just stare out the window, enjoying the feelings of tranquility. I even wrote some code once that I'd been struggling with before I fell asleep. The dream recall is intense -- you can remember every detail, rather than fighting as it fades away -- so I also started keeping a brief dream journal.
I'd love to do it again, but it's not feasible given the rhythms of NYC. If I ever move someplace quieter and decide to simplify my life, I'd eagerly return to the segmented sleep schedule.
Fun! I think a lot of students find an optimal sleep pattern, just because they can (depending on schedule).
There was a year that I slept from around 3am to 9am, long-ish siesta in the early afternoon (1pm-4pm). It was the most productive time of my life, and I felt well rested. I really got a lot of work done in those late evenings/early nights; Everything calmed down in the dorm, noise outside was lower. Morning was for chores/part-time job.
I wish I could return to this. I'm more or less 9-5 now and always tired.
Compared to lets say a regular siesta which many societies don't do, but I think we all have had or wanted to have an afternoon nap.