After taking the mender of the roads to Versailles to see the royalty and nobility, why does Defarge tell the mender of roads "You are the fellow we want"?

From the text;

The man moved a little further away, as soon as he could, and the mender of roads fanned himself with his blue cap: feeling it mightily close and oppressive. If he needed a King and Queen to restore him, he was fortunate in having his remedy at hand; for, soon the large-faced King and the fair-faced Queen came in their golden coach, attended by the shining Bull's Eye of their Court, a glittering multitude of laughing ladies and fine lords; and in jewels and silks and powder and splendour and elegantly spurning figures and handsomely disdainful faces of both sexes, the mender of roads bathed himself, so much to his temporary intoxication, that he cried Long live the King, Long live the Queen, Long live everybody and everything! as if he had never heard of ubiquitous Jacques in his time. Then, there were gardens, courtyards, terraces, fountains, green banks, more King and Queen, more Bull's Eye, more lords and ladies, more Long live they all! until he absolutely wept with sentiment. During the whole of this scene, which lasted some three hours, he had plenty of shouting and weeping and sentimental company, and throughout Defarge held him by the collar, as if to restrain him from flying at the objects of his brief devotion and tearing them to pieces.

"Bravo!" said Defarge, clapping him on the back when it was over, like a patron; "you are a good boy!"

The mender of roads was now coming to himself, and was mistrustful of having made a mistake in his late demonstrations; but no.

"You are the fellow we want," said Defarge, in his ear; "you make these fools believe that it will last for ever. Then, they are the more insolent, and it is the nearer ended."

"Hey!" cried the mender of roads, reflectively; "that's true."