I'd be more interested in saying that they haven't been so bad this season in Serie A, but they haven't been strong enough to exert more pressure to be a title contender. The top two teams last season had to admit that Napoli's performance was better than them and the two teams, either Inter Milan or Ac Milan, had to find the right solution for next season.
Jose Mourinho has brought changes to Roma this season, Roma will target to finish in the top 4 and the team they will get rid of may be Ac milan or inter milan in reaching the top 4.
Napoli's appearance this season has been truly extraordinary, the results they achieved today were certainly not in the predictions of previous people. Actually, AC Milan and Inter Milan were strong candidates to win the Scudetto this season, but their inconsistent performances made them fail to keep that chance, so that Napoli was very comfortable running alone without anyone being able to disturb him.
In my opinion, the competition for the Scudetto this season will be very interesting if Juventus don't get punished. Even though they started the season limping but slowly they were able to shoot up to the top flight. It must be admitted that Juventus do have a different mentality from other teams in Serie A. Just look at their current position after the point deduction occurred, with quite a lot of matches remaining, it is possible that the Old Lady will be able to take fourth place.