To be fair, CR7 with Juve is doing exactly the same he did with Madrid. Dissapearing on most CL important matches and randomly scoring 4 or 5 against teams that his team would have beaten anyway.
If Juventus's board and fans expected CR7 to bring them to the next level, they failed to do their proper research. Madrid's CR7 was a sum of its parts, and it was Modric, Bale and Ramos that had the most impact on most of their CL wins.
Yes, CR7 is a world class striker, he wil finish his chances, but he's still completely dependant on what his team does and the chances they create. He will score 7 against a team if he gets 9 chances, thats how clinical he is. He wont change the course of a game by himself though.