It's so everybody doesn't just swing their hammer around wildly without consequence. It makes you think out where and when you're going to swing. Otherwise two or more teammates could swing their hammers offset of the other and have this nonstop hammerstrike that has no opening for a counter.
Except people do that anyway...and in many cases it's the other players doing something stupid that usually get's them killed.
Sometime's I get pinned by 2-3 enemy's, I know I can counter easily (some games are like that), then some random team-player thinks it's a good idea to run in between us...regardless how painfully obvious that they have zero chance of surviving and actually causing my own death due to blocking my attack.
I've been in match's where I've completely wrecked the opposite team, yet players know when to keep their distance, attack at appropriate times and there are players that run in thinking there invincible, constantly get in the way...including times where they betray the person scoring.