I don't generally complain in a restaurant if something is not to my taste, only if food is unsafe or really bad. Today we visited a steak house for lunch that has great reviews both online and with locals. The food was dire. The chef proprietor was a nice young guy and had only opened 5 months ago. I couldn't tear into him in front of other diners, and I wouldn't want to slate him on tripadvisor. However, in his position I would want to know if a customer was seriously unhappy with my food. Would a polite email be in order?