What's so great about being happy?

Mari Ruti, a "critical theorist working at the intersection of Continental philosophy, psychoanalysis, and feminist and queer theory", in the Chronicle of Higher Education: Happiness and Its Discontents

Needless to say, our fixation on the ideal of happiness diverts our attention from collective social ills, such as socioeconomic disparities. As Barbara Ehrenreich has shown, when we believe that our happiness is a matter of thinking the right kinds of (positive) thoughts, we become blind to the ways in which some of our unhappiness might be generated by collective forces, such as racism or sexism. Worst of all, we become callous to the lot of others, assuming that if they aren't doing well, if they aren't perfectly happy, it's not because they're poor, oppressed, or unemployed but because they're not trying hard enough.
If all of that isn't enough to make you suspicious of the cultural injunction to be happy, consider this basic psychoanalytic insight: Human beings may not be designed for happy, balanced lives. The irony of happiness is that it's precisely when we manage to feel happy that we are also most keenly aware that the feeling might not last. Insofar as each passing moment of happiness brings us closer to its imminent collapse, happiness is merely a way of anticipating unhappiness; it's a deviously roundabout means of producing anxiety.