Quote Originally Posted by HyoMinPark View Post
I suppose because, during HW, Diurnal actually gave you more than just access to regens. It had passive enmity reduction and also gave faster recast and a small healing boost (like 5%). If I remember correctly. Noct gave +10% healing boost but no faster recast.
HW Start :

Diurnal : 5% cast and recast time
Noct : 5% healing spell increase

Later on : (~3.2 to 3.4)

Enmity reduction on both
Noct 5 => 10

Then in SB :

Diurnal : 10% healing
Nocturnal : 15% healing

(I know it's detail, but the idea is here, it used to have another purpose before that was not only adding a side effect to aspected benefic).
Now they could give both diurnal and aspected benefic at the same time (just like scholar getting aetherflow and lustrate in lvl45)