Essance Reaver. Critting to gain back mana.

Is that really necessary? I loved ER on champs like Yorick, Jayce, AD casters in general. It was such a more aggressive option for me to go instead of the lame tear route. Now if I wanna make use of the mana regen on it, I have to start building crit on AD casters? That sounds unfair and honestly a bit of an identity crisis with the item. Personally it feels like it was made for AD casters. It gave good AD, CDR, and more importantly a way to gain mana back just by auto attacking.

But now its gonna require you to land crits to gain back mana? Why?