People engaging in outdoor sport, or training for that sport, usually do it on a pitch or playing field with the general public excluded, apart from spectators who are restricted in where they may sit or stand, and in any interaction with the players.
However,cycle sport is completely different in that particpants or those in training mingle with the general public, perhaps it is this difference that causes the "problem" being discussed in this thread.
Members of the public passing sporting venues would not expect acknowledgemt from golfers, tennis players or javelin throwers as they train for perfection in their respective sports, Why then should they expect acknowledgent from the helmet, lycra, goggles and expensive bike brigade, who are quite clearly engaged in cycle sport?