"There must be a system in place where aggressiveness is actually encouraged"

yes, they need to change the rules and quickly ,

we might never see Floyd lose

 

Do you think Mayweather moved backwards or did Mayweather more often than not hold the centre of the ring?

 

Floyd was trying to hold the center of the ring, but when Pac started walking toward him, as predicted he would move away or side to side towards the ropes / corner. That's really a textbook example of Pac being the aggressor. Pac was forcing May to move and back away from him. That's what an aggressor does, he moves towards his opponent.

By definition Pac is the aggressor, and Floyd is at his best when he is being defensive and looking to counter the opponents aggression. Being aggressive, or being the aggressor is all about taking risks, pushing the pace and creating exchanges, walking towards your opponent to land as many punches as possible. Why the punches thrown were about even was mainly because Floyd was able to move away from Pac so skillfully that Pac had a difficult time actually getting into that punching range. And when he did manage to get into that range Floyd would time it and throw punches himself. So the punches thrown ended up being about even.