My answer (ripped from the GCL thread):

There's no real wrong or right answer as to whether or not defending or attacking is easier/harder. There's too many variables. What kind of character are you playing? What are they playing against? What are the weapons? The powers? The environment?

Are you fighting a counter-boxer, an out-boxer, a swarmer? A swordsman, someone with a spear and shield? Do they have armor? How much? What kind? What kind of powers?

There's enough variables that you can't definitively say one or the other is easier, especially when "attacking" and "defending" are very broad topics. It's going to vary from situation to situation, and part of being a good fighter is knowing when to attack and when to defend.