I think their performance did not disappoint, they made 10 attempted shots and 4 shots on target, besides that they also dominated 53% possession in the match. Juventus were just unlucky because they missed the golden opportunities they created.
The absence of Pogba in the match is not a reason for them to lose, we can see from their match against Sassuolo, they can win easily even without Pogba. But of course, we'll see a better Juventus performance if Pogba later recovers from his injury.
The match against Samdoria was proof that Juventus actually needed a better striker. Di Maria who could actually help the attack become more sharp, but was not seen in the Juventus line-up in that match. Obviously that leaves Juventus with no better option when they are struggling to score goals. Finally, a goalless draw was inevitable even though Juventus played well and created many chances.
Juventus' next match is against Roma who are currently at their best. Roma are not so sharp, but they have won 6 points in the last 2 matches, and that should be something Juventus have to watch out for.