Valère is a nice guy who very nearly finishes last. Sure, he and Mariane have a little lovers' spat, but there's not much else wrong with him as far as we can tell. He's simply a victim of circumstance, circumstance in this case meaning Tartuffe's trickery. He comes through when things are at their worst, showing up at Orgon's door with a getaway car and a thousand smackers – so we know he's the real deal. Only through the intervention of the King, though, does he get the girl.