I don't think so. Which things that makes you think if the performance of juventus is really poor this season? Juventus is still having a chance to be qualfied for UCL.
Juventus did not begin this season well but later they improved and got a good streak to move to a third position. After that they suddenly got a big point deduction and fell down to nearly bottom of first half on the table. Again they improved and came closely to top four so in general I don't consider their performance is too bad.
However, it is not enough for them to compete with Napoli even if they have 15 more points (without the deduction). They must buy some players for their squad to compete with Napoli in a next season. Obviously they should focus to complete this season in top four first.
If it's not caused by the sanction and juventus is still sitting in the second place right now, 15 points as sanction is really big in my opinion.
Without the 15 minus points, Juventus would have stood on the second position, not Lazio. They would have gotten 56 points if they had been deducted 15 points. Lazio now only have 52 points totally.