Why is Ziggs Q so hard to land?

I'm finding it rolling right by someone within close proximity or even hopping over minions and enemy champs. I find it should have better proximity detonation; I laned up against an Oriana as I was playing Ziggs and her ball does so much damage with one hit and hits such a wide area meanwhile my Q misses 85% of the time. The best chance to hit the enemy is if they stand directly behind minions and i can catch them with the splash damage. If I want to hit them in the open I literally have to anticipate which degree of an angle to throw it on because its so easy to dodge unless I throw it directly on the player but to do that I have to get real close and any gap closer champ will have a field day with me.

I've had a lot of sucess at mid lane but Ziggs is not that champ. I main Ezreal and have been using skill shots most of the time so im not inept when it comes to skill shots but Ziggs Q is a rage inducing troll.