The guy next to me can't help but publically complain about every client email he recieves, every piece of feedback that needs clarification. He brings other people over to bear witness to the stupidity of the people asking for his skills.
The other people in the studio will laugh, and agree, that was a terrible and stupid thing for them to ask for. And, back at our desks, all of us are left thinking, yeah, our clients can be pretty stupid, too. They don't understand video editing, or page layout, or what exactly Photoshop can and can't do.
But this kind of thinking allows us to put other people below us because of their lack of knowledge in our field.
And this is why cynicism is so deadly: it helps us forget that we're not just designers or photographers, but that we're also advocates and educators for our craft, and sometimes, mediators.
Sure, they may not want to hear their slogan idea is terrible, or that the background for the leaflet shouldn't be hot pink, but you owe them your counsel. And then if they don't like it, well either you presented your argument poorly, or they need to find a worse designer.