This is not necessarily a bad thing. As an employer, you want to employ workers that share your company values. In the example of Stan McCullars, he expressed views that went against the values of the County clerk's office. He was not only right to be let go, but it was beneficial to the clerk's office to be made aware of these beliefs.
Consider, for example, someone in charge of enforcing equal opportunity laws in their professional life, harbours racists beliefs. In their personal life, they frequently express these beliefs both verbally and in their actions. It is in society's best interest to expose these people for living double lives so that someone better suited to the job can be found. Social media can act as that exposing force, as it did in the case of Stan McCullars.
In this way, social media outrage that shines a spotlight on individuals that transgress, is a positive force in society.