Because he never shows up?

… Why We Keep Waiting for Godot | Literary Hub. (Hat tip, Dave Lull.)

Because of Beckett’s demands, productions of Godot rarely change. And although theaters have ignored his dictates, what he wanted is what we most often see: four male actors, the dead tree set, the uncut dialogue, the gloom. Where Shakespeare’s words are endlessly adapted—cut up, re-worded, placed in new settings such as the controversial production of Julius Caesar at the Public Theatre’s Shakespeare in the Park this summer—Godot does not change to suit us. Among our own changing circumstances, it abides.