Skrillex plays Bumbershoot’s Mainstage at 9:30 p.m., Monday.By David StoeszThe Bumbershoot website lists 68 musical acts by my count. Of those, exactly seven are African American. The rest are mostly white, with a very small smattering of Asian faces and “global” artists like Omar Souleyman (“global” is apparently the new “world”).If you made a stack of Diet Pepsi cans, with each can representing a Bumbershoot musical act, the stack of Diet Pepsi cans for black artists would be three feet tall, and the one for (almost entirely) white bands would be 28 feet tall. While the all-honky lineup in the Americana category may not be surprising, the disparity also holds for both hip-hop (only two of nine acts are black) and blues (zero point zero black people).The unbearable whiteness of being Bumbershoot is not racist. It’s a cultural thing. Seattle suffers from a Stuff White People Like monoculture. We’ve revered the same cultural touchstones (Where the Wild Things Are, Joy Division, Ira Glass, etc.) for so long that we’ve gotten thoroughly cozy with ourselves. There’s nothing necessarily wrong with that. There’s nothing wrong with the Caucasians I saw gathered in a circle one recent morning at Golden Gardens, all wearing super-spiritual stretchy clothing and identically clasping their hands together in some kind of self-improving yoga prayer. No crime is being committed by the knee-slapping, neckerchief-wearing bunch that gathers at the Tractor every Monday for Square Dancing Night.But breathing your own breath gets pretty stale after awhile. There’s no better place to witness the stagnation that’s set in than this year’s Bumbershoot, where the headliners include an over-the-hill, overexposed crooner and a one-hit wonder whose name one can pronounce (Got ya? Goatee yay?). Is this really the best the organizers have for us? Mighty white of them.