Why are we unable to respond to customers/consumers FAQ in public setup on the counter,phone and online up to his entire satisfaction?

They sometimes feel noboby really cares about their feelings or complain,so they need to vent out their frustrations to get undivided attention. 

Sympathising with them will calm them down,as trying to put oneself in their shoes, per say.

They also use the 'customer is always right" policy to the maximum.