The simple explanation is:Balance purpposes.
Yeah, but we never had any balance purpposes on mystics and Might Swyng.
They're already waaaaaaaaaaaaaaay too OP.
It's related to soulforce, so it's not really bypassable.
SoR is bypassable with a simple hit, Soul of Silence with Will Surge, Soul of Stunning with any anti-stun skill, pot or Faith/fortify on genie.