Because bowing to him will confuse him, so that you will be able to deliver the first blow?
So, it seems that you are saying that bowing at times carries absolutely no form of respect and is used as a form of deception. That is pretty far out explanation, I think, far from how bowing is used in Aikido. That sounds to me like insincerity and bad manners.
I think that bowing is akin to saluting in the military. In the military, since everyone is forced to bow, er, I mean salute, it can almost seem to be an empty sign, especially when one person really doesn't like the other. However, at the very least it still contains the acknowledgment of a higher rank, a form of respect.
For those who think that bowing is a form of worship, then consider that a bow of respect is different in that with respect, it is returned.
Consider that someone who is being worshiped is not going to get down on their knees and return the bow. The exception to this is if you are apologizing for something or if you work at department store in Japan. A little off topic, but if anyone ever feels the need to be worshiped, just go to a department store (like Keikyu) in Japan at opening or closing time. All the employees will line up and give you a deep 90 degree bow, looking straight down at the ground, with a welcome in the morning, and a thank you at closing time. It's great!