Does prior appointment with the Administration violate citizens' rights?

Appointments have become the "normal way" to access procedures and services in the Public Administration. But is it an acceptable practice, and does it really serve the general interest? 

In this video, Fundación Hay Derecho and Manuel Villoria, member of the Network for a Culture of Lawfullnes and the Fight against Corruption [2], question this figure that could infringe on the rights of citizens.