Yes, Smart People is sexy, but is it really smart enough?
Eunice Wong and Roderick Hill hook up for some hot identity politics. Photos: T. Charles Erickson.All good plays cast long shadows, so perhaps it's unfair to feel disappointed with Lydia Diamond's Smart People (at the Huntington through July 6) which is indeed smart, and often entertaining, but never quite emerges from the penumbra of Stick Fly, the playwright's unexpected hit of four years ago. And the reason …