It's really a big surprise that a great soccer nation like Italy doesn't participate in the World Cup twice in a row.
In the meantime, between those two world championships, they were also European champions and showed that they are a great team, so the surprise is even bigger.
In the qualification group for the world championship, they were second, behind Switzerland, and in the additional qualifications they lost to Macedonia.
I watched that game against Macedonia and Italy was a much better team but they couldn't score a goal. Macedonia scored a goal from practically the only real opportunity, in the last minute of the game, and beat Italy.
I would say Italy was just unlucky.
For me actually, it is not a very big surprise because Italy has not been doing well recently and I am not going to say that there did not deserve to play in the world cup but they have also not been playing like a team that deserves to play in the world cup. And I also agree that they have been really unlucky in some cases. But whatever you say they cannot just concede a goal at that time of the match against Macedonia.