Its other abilities are solid even before that, making it a reliable planeswalker for any white-based deck
Evacuation again at instant speed, the fact that it removes all creatures doesn't hurt us too much since we run few, and holding onto it until we are in fact getting attacked is pretty relevant IMO
This presents a very large problem as your Prized Amalgams and Bloodghasts will have trouble attacking through large vigilant, first striking, lifelinking creatures
Unlike a certain commander who gives opponents card advantage when trying to hurt them, Sheoldred, The Apocalypse only focuses on making drawing cards continuously damaging for them and great for you the added deathtouch makes your enemies think twice about blocking damage, keeping the game plan simple enough that the card will always be in high demand
That being said, she can benefit pretty greatly from replacement effects that affect token generation (such as Academy Manufactor) and/or tap-based Stax effects like Stasis (as long as you have the means to untap her)