I think it's the appeal of the multitasking abilities: cracking walnuts and the like.
Honestly, I think the Cap'n is correct in regards to those looking for functionality in their pipes, but I've also seen a great deal of Youtubers enjoying them--and advertisement is a powefull thing.
I've noticed masculine designs have been popular lately as well, and the 320 is stout and beefy. Perhaps, also, that it can sit, is portable, and has a large bowl capacity--which makes it convenient.
I wanted one, thinking it would be an ideal comrade when writing; but, personally, I haven't enjoyed the one I bought nearly as much as the 311 [poker] I picked up in December. Personal preference, I suppose.
Maybe I should buy another before I write them off?
I hope you enjoy yours, sir (if and when you've purchased one)! I have to admit, the Oceano series is tempting.