I try to understand that, when eating in any place, humans are cooking and serving the food. I always figure if my food comes out pretty close to how I like it, I'm fine with it. If the server is truly trying to provide decent service, I consider it a good experience. However, if I order french fries and get hashbrowns, ummmmm......... take it back and bring me what I ordered. The server is the last link of quality control when the food comes out of the kitchen. The ticket should be compared to what's on the plate and the correction made before the plate comes to the table. Failure to do so get a ding in the server's performance.
I could go on, but, let me say that it takes quite a bit to make me consider lowering my tip to the server. They have a tough job and I try to be the customer they LOVE to see come back into the joint.