In any country or empire, no matter how big or small, there were always places like the black market. When Aries ascended the throne, she realized that aside from other state affairs; the emperor had been monitoring the black market in the empire.
Abel could've completely vanquished it if he so pleased, but the reason things such as this existed in the empire was that he allowed it. In his defense, it shouldn't be just utter peace or total goodness. At that point, Aries wasn't surprised because she heard stories about rebellion and even read the records. If she didn't know better, she would think it was the natural cycle of any country.
But alas, Aries was aware some of those rebellions were incited by Abel's people — sometimes, Conan or Dexter would fuel the people.