What other system would even work though? In all the MMO's I've played, you ALWAYS want to be casting something, keeping the GCD rolling in combat. Like, I really don't know what else would work, unless we wanna go back to the days of sitting in combat to regain MP(please Lord no.)

Also, I don't think it's an opinion, more so hard math. The one pressing buttons when possible, and thus keeping the GCD rolling(assuming not a broken combo spam) is always going to do more than one that only presses a button once every 4 seconds.