DespairsRay's tour was a cluster fuck because didn't they have Visa issues right before the tour start?
Anyway, I was just going to pipe in but it seems like most Japanese artists always play at Showbox in Seattle. So I wouldn't look into too much in regards to who plays where in the US. I think it's just whoever is booking the bands are just familiar with Showbox than other local venues.
The exceptions would be Loudness, Church of Misery, Sabbat and Sigh playing at the typical local metal venues but that's probably because they're associated with those metal labels and promoters that regularly book at these venues.
I'm only speaking in regards to Seattle but I imagine that could apply to other cities as well.