it is not just that. There are many parties, yes, but they tend to run together.
in this election, however, we have at least 4 main sides, which is unusual, since 3 of them are taking a very high number of votes ( such a support for a third side is unheard of in my lifetime).
Furthermore, there is a fair chance that one of the houses of the parliament will go to the left, and one to the right. since the parliament holds all the power here (unlike for example in the US where you still have a president), a split parliament means no chance to pass any law.
and even if both houses are won by the left, or by the right, the senate will still lack a decent majority. and should the right be the one that wins( they currently have the lead in the senate), they will have great trouble because we have life senators ( ex presidents of the republic, and a few important people, usually nobel prizes), and they are usually leftist.
alliances aren't possible or even useful, because the 5-star movement took 1/3 of the vote, and declared its unwillingness to ally. left and right can't really do a long term alliance after the last 2 years.
said with less words: it is an huge, huge mess.
edit: yes, italian government isn't the best possible one to deal with multiple parties. It is assumed that parties will band together, and push a compromise program. But sometimes, it breaks.
a corrupt political class doesn't help either, but that is another matter.