It doesn't make sense for Napoli to deliberately lose a competition they still might win, to me it's just an absurd assumption. Napoli have experienced a very significant drop in form this season after winning the Scudetto last season, so they need to take advantage of every competition to win it instead of letting other teams beat them easily.
Yes, this is a realistic thing. It will be very difficult for Napoli to reach the top of Serie A this season and defend the title they won last season. Not only is their condition quite poor, but the distance between points is far away and the strength of the opposing team is actually getting better this season. The competition is very tough this season. And what's more, at the moment, I'm sure Mazzarri's focus is on improving the performance of his squad and trying not to fall into an even worse position. Because after all, Mazzarri also has quite a tough challenge here. At least if Napoli can still enter the UCL again next season, this will be enough for now.
Even though Napoli failed in the Coppa Italia with quite a big defeat. But at least there are positive things that Napoli can take after they out from the Coppa Italia. Namely they can focus more on Serie A and UCL. I hope Mazzarri learns from the mistakes he made in the match against Frosinone in the Coppa Italia. And I hope Mazzarri can really bring good changes to Napoli in Serie A and in the UCL.
Although currently Napoli is 14 points behind Inter Milan who are at the top of the standings. But Napoli still has the opportunity to work harder to get a ticket to the UCL next season. And work better at UCL. Because realistically I also think that Napoli are out of the title race and will only be in the hunt for the top 4 rankings. Because the point difference is widening, it is certainly difficult to catch up Inter with Napoli's current condition.
Last season Inter Milan also only targeted the top 4 rankings and they focused on the UCL. I hope Napoli can do the same thing like Inter Milan last season.