The country of South Korea is in danger of a popular revolt. Citizens are losing faith in their country's government; certain top executives are deemed to big too jail. This will likely create a lot more hostility in the nation toward government officials and top executives. The country is in need of ethics reforms.
South Korea knows that all eyes are on them and on their political system. It's important that South Koreans be able to show the rest of the world that they are a free country. They need to show the world that law and order are enforced. The people know this and they want the laws applied evenly.
If single person is beyond the law, than the government is not strong enough. People want to be treated fairly and equally. If citizens feel their government is not for the people, than that government will not be in power for long without facing resistance. South Korea can not let government corruption pass without a fight from its citizens.
South Korea is not in danger of a popular revolt over the Samsung error who is facing corruption charges. While playing favorites does not look very good in this case, it happens every day in every country, Mostly to important people. Think about it for a moment, South Korea is actually correct in their reasoning.