Well Miche2 I completely agree with you those comments should not have been made by all the crew on your many flights.
Did you comment back? Did you complain to anyone about it? Did you ask for a Global Perfomance Monitor? Did you write into the company. Did you take the flight number and there details and do something about it? There are numerous things you can do and could've done. Unfortunately these crew will keep on doing this and nothing will change unless something is done about it and the company informed.
I can clearly see that your upset about it however sweetie I can guarantee you nobody does that on any flight that I've ever been on. I have found the crew at BA to be better than most.
As to where the attitude stems from. To be quite honest I've not experienced it on BA so i guess the answer would be:"Nowhere"