Toward the end of Matthew Barbot’s new play, “The Beautiful Land I Seek,” a writer in his 30s, plainly modeled on Mr. Barbot, is asked if his plays are political. After making what’s described in the script as “a kind of useless gesture,” the character responds, “I mean … I kinda think everything is political, right?” Sensing his questioner isn’t satisfied, he adds, “I write all sorts of things, but people seem to like the identity plays best.”