IIRC this is intentional. I thought some Rioter's have said Orianna is bascially a "balance pillar" that they try to touch as little as possible because her numbers are what they want damage to look like on a broad scale.
Usually the lever they pull if they must balance Ori is her ult. Wonder why they finally touched the Q.
Not sure when that was said if ever but there are no champions that we currently view as a "balance pillar". But also wheee Orianna buffs