It depends upon many, many things about the person. IMHO, it gives the button pusher a sense of "control" over you by triggering some emotion in you. They get some inner satisfaction at knowing they can affect you that much. Some may not realize they are truly getting a sense of victory, control, satisfaction or whatever....but they do. Even when it is not the result that the button pusher was seeking, I believe many continue to "push". But, if their tactics no longer works on your reaction, then they will run out of things to do and finally give up.
If you look at these threads of LBS's, you can usually tell when the WAS is pushing buttons big time. That is why it's hard to play it cool--drop the rope, etc.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!