I do fine with Ornn in ranked. Not sure what the problem is. I mean for one thing, what are you supposed to do? Never use a new champion in ranked, ever, at any time in their lifespan? You learn champions in normals. PBE is normals. If someone played him in PBE and got comfortable with him, it counts.
190 ping? That's pretty low on average. Every game I get two or three players reporting 300+ ping, and I manage to play with around 250 from Japan just fine. Not sure why that somehow makes them easier opponents.
Ornn is statistically weak, and no, he's not OP. You're right. That's exactly why I play him. It's not about stomping and playing what's OP. It's about outplaying the opponent. That's the spirit of competition. You'll never improve if you just pick the safe, comfortable picks and expect to walk over everyone. Stats be damned, Ornn is fun to play. And played correctly, he does extremely well, in ranked or outside.