You’re right, because the effectiveness has been demonstrated clearly in those rare dioceses with strong bishops who do use their authority for public discipline. Men like Burke and Bruskewitz. We see that the parishes in these places have high Mass attendance, high attendance at adoration and other devotions, and that there are more vocations to the priesthood, and active pro-life efforts. I’ve also heard that in individual parishes the priests have fewer liturgical abuses.
So maybe it’s not merely that the public figures are called to account, but that somehow that clear demonstration of the faith reassures and strengthens the average Catholic layperson. The bishop’s actions in one case become a means of both teaching and sanctifying the many, without needing to do anything different in how he governs them, because the truth becomes evident to all.
The reverse is equally true -- if the bishop is seen as a weak-kneed wuss who's more afraid of offending the 'spirit of the age' or political correctness than he is of God Almighty, his flock thinks, "Well, he doesn't take it seriously, why should I?"