Why do people rage over needing to shield block for the Phalanx > Spirit's Within combo?

Aegis Boon is a 100% physical block that you can use at will. Wait for a physical attack or physical TP move, pop Aegis Boon, recover the HP from it's effect, use Phalanx, use Bloodbath, use Spirit's Within.

With the new low cooldown on Spirit's Within and the already nice cooldown on Aegis boon, coupled with the non-existent cooldown on Phalanx, it's not bad, or hard, at all.