It's a class war, silly.
But although Lander’s designation is peculiar, he’s hardly the first to dissect this elite and its immediate predecessors (see for instance Mark E. Kann’s Middle Class Radicalism in Santa Monica, Christopher Lasch’s The Culture of Narcissism, Richard Florida’s The Rise of the Creative Class, and David Brooks’s Bobos in Paradise—Brooks calls these people variously “bourgeois bohemians,” the “educated elite,” and the “cosmopolitan class”). Lander, like many of these writers, traces this group’s values to the 1960s, and there’s clearly a connection between a politics based on “self-cultivation” (to quote the Students for a Democratic Society’s gaseous manifesto, the Port Huron Statement) and what Lander defines as White People’s ethos: “their number-one concern is about the best way to make themselves happy.” That concern progresses naturally into consumer narcissism and a fixation on health and “well-being”: Lander’s most entertaining and spot-on entries dissect White People’s elaborate sumptuary codes, their dogged pursuit of their own care and feeding, and their efforts to define themselves and their values through their all-but-uniform taste and accessories (Sedaris/Eggers/The Daily Show/the right indie music/Obama bumper stickers/uh, The New Yorker).
So why call this group “White People”? Lander is almost certainly being mischievous. After all, dismissing something or someone as “so white” has long been a favorite put-down among those who like to view themselves as right-thinking, hierarchy-defying nonconformists—that is, White People. Recall those ads extolling “the new face of wealth,” which contrast male, stone-faced WASP bankers with attractive, far less formally—though far more expensively—clad women, quasi-hipsters, and assorted exotic ethnics. The women and hipsters may be white, but they’re not white—they’re members of the cool-looking pan-ethnic tribe, a tribe defined by economic and social status and by cultural and aesthetic preferences rather than by ethnicity. When I interviewed Lander on the telephone in July, he acknowledged that White People are in fact “desperate to define themselves as other than white.” Indeed, he rightly places “diversity” and “tolerance” highest on the list of virtues prized by White People (as did Brooks for Bobos). "Intolerant Chic" by Benjamin Schwarz
As Tom Wolfe pointed out, as a white person you gain status by demonstrating bending-over-backward altruism, or potlatch.
So you have these white people who are ashamed of their own origins as impoverished Irish or Slavic farmers, or wops or Jews, and they're trying to use their benevolent attitude toward people they obviously consider inferior, all as a means to lift themselves up personally in social status.
That's why we like Stuff White People Like, and it's why I'm re-reading David Brooks' Bobos in Paradise: The New Upper Class and How They Got There: they point out how in the intra-white class war, minorities are just sad pawns.