Sure, that must be why sites like this exist for Italians, specially the Northern Italian separatists and their well-known "we are just like Central Europeans and not like those swarthy southern Europeans/Mediterraneans" strange obsession, while no such thing exists for Iberians:
http://racialreality.110mb.com/padania/
http://racialreality.110mb.com/leganord.html
And ironically you are in fact responding to one who does exactly what you think Iberians do.
The real reason why it seems easier to try to pick on Iberians is because most people really don't know much about the history of the place. They hear popular silly lies and myths, strongly propagated by Afrocentrists, Nordicists, Muslim radicals and other charlatans with agendas, like the one spewed around here earlier about a supposed "800 years of Moorish domination of Spain", and more often than not start jumping to (incorrect) conclusions. One only needs to bother to dig a bit deeper into what actual historians specializing in the history of Islamic Iberia say to plainly see something quite different from these myths and lies. For starters, most Muslims in Iberia were in fact just natives who had converted to Islam, the Arabs and "Moors" were only a small foreign elite. Nothing "odd" here, really, at least not to anyone familiar with history. This is the same pattern of most military invasions throughout history. They are not large migrations of people. On the other hand, most people are not acquainted with Italian history as well as they think they are. A lot of people completely ignore the quite large communities of free and enslaved foreigners, particularly from the Eastern Mediterranean lands, in Roman Italy, something that is pointed out by a slew of experts on Roman history.
And you can easily put to the test your very own theory that Italians are more "confident" and that not responding to people trying to pick on a nationality will just make them go away and stop: make accounts for specifically targeting Italians and go around internet forums pounding them all day long with things like this:
http://www.giveshare.org/babylon/racechange.html
And calling them "Syrians", "Anatolians", "Semites", "Jews", "Egyptians", "descendants of slaves", "fake Latins/Romans", etc. I guarantee you that the "complex" that you think Iberians have will be in full display by Italians as well. That's because that supposed "complex" is really called "defending yourself from lies, exaggerations and distortions by people who obviously don't have very good intentions in mind, that's why they are lying, exaggerating and distorting things to begin with". Curiously enough, it seems that some people think it's only a "complex" when the much dreaded "Iberians" do it, but when others do it it's just fine and dandy.