I think Italy's situation is due to several factors, such as those mentioned above. I also read yesterday that about a third of Italians defied the lockdown.
Howiever, I think it needs to be considered that they were the first European country to experience this kind of spread of the virus, even though it seems that it actually first came to Germany via the company Webasto. That company had an employee from Wuhan visiting, but also operates in Northern Italy. So it's likely that an Italian or Italian-based employee contracted the virus in Munich and then carried it to Italy.
The thing is, in my mind, without Italy other European countries would not have been able to push through measures like those we are seeing now. There simply wouldn't be acceptance for that. No one would take it seriously enough. It is because of the stories coming out of Italy that people in other countries accepted the reports about exponential growth and that drastic measures are the only way to slow the spread.
Speaking from a German perspective, there are two opposing forces at work here: On the one hand, Germans are known to follow the rules. And that's what a lot of people are doing. But they do so because they see what's happening in Italy, and therefore they are taking the warnings seriously. But then there's also the historic knowledge of the dictatorships, especially the Third Reich, which has people almost paranoid whenever any freedoms are being curbed. These people fear that everything is just the precedent for a new dictatorship coming and enforcing a new brutal regime. Some of them may still have realized the dangers of Covid-19 and self-isolate, but then there are those who think this is all more fearmongering than anything else, and they need to defend their freedoms.
And of course there is no small amount of people who just think they are stronger than the virus (which they likely are, but that's of course besides the point).