I'm a huge Rubio fan, I have been since he was 14, and not following from afar, but watching him closely every step of the way (and when it comes to his NBA career, I haven't missed more than a handful of his games). And this is, without a doubt, the worst I've ever seen him along with a really rough stretch during his FC Barcelona days. He simply doesn't look like himself. He's always been a master of the entry pass and we're seeing none of it (last night's pass to Favors was the perfect example), he's not running the team efficiently, he's not picking the right plays time after time like he's always done and he's rarely created something out of nothing since the season started. I also don't like it one bit when he scores a couple of buckets and he suddenly gets overexcited and more prone to TOs or taking bad shots. That's just not him. He's still excellent on D on what's the most difficult position to defend in the NBA nowadays, and he'll bring the energy every night, but right now I'm not seeing anything that even resembles the Ricky Rubio I've been a fan of for 12+ years now.
IMO there's not just one factor going on that's affecting him, but rather a combination of circumstances. Being in a new team after all these years is one of them, and so is playing on a system where there's not really one guy directing and generating for others, but rather plenty of handoffs and movement around the perimeter with the ball usually going through many people's hands (even if they're not always creating anything per se). But it's also on him to be able to make the most out of his touches, to get in synch with his teammates, to find those passing lanes that nobody thought were there, and to play within himself and not commit silly TOs (fortunately he's already cutting on those, so I'm hopeful the rest of his game can follow).
I have never had a problem with Rubio being a poor scorer. He's always been a net positive with his defence and his craft running an offense, and he's always been exciting as hell to watch with his intensity and his incredible ability to find guys anywhere on the court. But that's not the Rubio we're seeing so far, and right now I don't think all that focus on scoring has been as good for him as everyone would've liked. I think it's gotten to his head and changed the way he plays, and now it's time for him to go back to the basics, be his old self again and forget about everything else for now. That's the best way to help himself and the Jazz for however long he's in Utah.