the idea in pve is, that instead of boosting everything else, you lower pretty much melee farming speed, so for example without CC, in GC you wont feel like sh1t if you go farm with your main mage party and no need to log your tyrant box party just to farm
same goes for other zones
CC was added in hellbound chronicle, so interlude PP didnt have it
also CC was working even worse in past chronicles in pvp, because back then you didnt have reflect damage from all source of dmg like now, so only time CC could proc is if some DD focused you and made enough dmg, on classic it procs after first skill because you reflect enough to proc it