You seem to have failed to see the thorniness of the problem maybe because in the current instance (Le Pen's ban by the French judiciary) you agree with the outcome.
I would only see thorniness is the courts refused to punish Le Pen out of fear of punishing a somewhat popular politician, as this would embolden others to act in ways to break the rules, and would undermine the independence of the court, which is a core tenet of a functioning democracy.
I think you only see thorniness here because you wanted Le Pen to keep doing her thing. See? it works both ways.