It’s so simple. What’s not to get?
It’s harder that yoyoing! That’s for sure.
I assume he means why do people like it (rather than explaining the concept of Kendama). I don’t get the appeal either, but I’m sure there are Kendama players who don’t get the appeal of yo-yoing, and jugglers who scoff at both.
It’s popular because it is inexpensive to get into. The concept is extremely simple yet it is pretty hard to master.
Have you tried it? It’s freakishly addicting.