Why the Japanese Obsession with Beetles?

I have mentioned a few times on here that I grew up in Japan.  I spent 12 of my 18 formative years in different places in the Kanto plains area, and I have Japanese relatives with whom I shared many holidays and important life experiences.  As such, there are certain things that don't seem out of place to me that are quite foreign to others.  For example, getting naked in onsen is no big deal to me.  I make sure to cover my stomach when I sleep so I don't get sick.  I like to eat unagi on hot summer days to give me energy.

But sometimes my wife (who loves Japan but wasn't raised here) asks why certain things are the way they are, and I just don't have a good answer.  

Here's a recent example: Japan's obsession with beetles.

So we were walking through the local Aeon department store, and we chanced upon this bad boy:

It's a kabuto mushi, or Rhinoceros beetle, and they were selling for just under 500 yen (along with a bunch of other types of beetles).

Having grown up here, I just know that kids in Japan love playing with beetles.  They raise them, breed them, show them off in school, and even fight them like little poke-masters against other kids' beetles.

Why beetles though?  I mean, there are thousands of other bugs and tiny animals that kids could catch and raise, but beetles seem to be the go-to choice.

To that, I didn't have a good answer.  They're cool looking?  They're easy to raise?  Nobody weeps over a dead beetle?  They look like tiny Kaiju?

I really don't know.  I even pored through my knowledge of Japanese folk tales and children's songs to see if there was a connection, and the traditional animals included are things like frogs, foxes, rabbits, tanuki, sparrows, cranes...but no beetles...

Can someone out there enlighten me, please?  Is there a reason other than "Well, that's just the way it's always been" why beetles are so popular???