Neither have I. For the record, and knowing only what I learned on this thread, I'd say the flight attendant was wrong.
My wife and I flew from VA Beach with our three month old son, and on take-off, he needed a little soothing to calm down. So my wife nursed him very discreetly, and the people surrounding us were very understanding and supportive---even thankful (i.e., no screaming kid). Seems like this flight attendant may have escalated this issue unneccessarily.