Yikes. I DO think about that from time to time. I will complain about the food in a restaurant...usually about once in every 40 to 50 dines. If you are going to complain, make sure you are able to see into the kitchen and have a good read as to what's going on. I usually would like to see who the chef/cook is.
PB, I really wouldn't expect quality from a "fern bar" - chain operated, brass rails, hanging plants, etc. And, hell yes, you have a right to complain. I think most people don't complain. I hope you got some reduction on your tab.
One of my friends in Portland with whom I would go to eat said I was very "East Coast" (which I am not) because I would almost always ask for something prepared MY way - either a swap of garnishments, deleting an ingredient, bleu cheese in which to dip my fries or whatever. That's their line of work. It shouldn't bother them. By the way, this is a request, not a complaint.
Weirdest dining experiences:
1. My Mom once got a broken off shard of a plate in her food at Olive Garden. The entire ticket was comped.
2. Over Thanksgiving, at an 'effin awesome Italian restaurant in Buenos Aires Argentina, an ambulance pulls up and the attendants come into the restaurant. It was taking forever for my food to arrive. Turns out my waiter, a very low key Fernando, had a bizarre drop in blood pressure and someone else had to take his place.
3. The two rudest dining experiences ever - a condescending waitress at a seaside restaurant in Sausalito and the jerky Mexican owner at an Italian restaurant in Sonoma (who gave me the up and down because I walked in wearing shorts, a t-shirt and thongs). Both times, no tip and, next to the tip space on the credit card, I wrote "sn*tch" and "a*s h*le," respectively.