I have not come across any really bad crew on BA. I have had one set of strange crew on BA, but they were certainly not rude - they just didn't seem to know what they were doing, which I found very unusual on BA.

I have had one actual 'bad' crew on a flight (not BA) who completely ignored one of the pieces of regulations and was also patronising and ignorant. I wrote a complaint to the airline about her breach of regulation and I believe this was followed up quite rigorously, as I received a phone call from the airline to discuss it in detail and to apologise to me about it.