Think the difference is that you've come to the conclussion that Di Canio = Fascist = Mussolini and others haven't.
My take is that he grew up with the Ultra's, still has a connection with them, made an arm gesture that they use a few times to them as a result and has an interest in Mussolini. I don't see him being a fascist as relevant as there are many interpretations of fascism, especially today, and I've seen nothing to suggest he supports any of the extreme elements of fascism that were present under Mussolini.
If you've got anything to back up the claim that he's just as bad as the Nazi's then share it and change our minds.
You've probably missed (understandably, given the huge swathe of stuff about this) the bits I posted in one of the many subsections of multiple threads where this was discussed about who he's saluting with the fascist salute - the Lazio Ultras. Who do explicitly and regularly identify with Mussolini; hold aloft banners adorned with swastikas, Totenkopf and other explicitly Nazi symbols; there's a photo I posted somewhere of them holding a pretty much stand-wide banner saying "Auschwitz your country, the oven your home"; they had a long infatuation with Arkan, one of the most brutal ethnic cleansers of the Balkan Wars (and held aloft banners mourning his death at several games) because they too were at the time engaged in their own minor but nasty street wars with Albanian immigrants. He admits himself that he came from the Lazio Ultras and these were the people he was saluting as his "camerati" (the Italian term used deliberately to denote members of Mussolini's Fascist movement).
It's simply not credible that this was some Gazza-flute-playing style act of crass ignorance. He knows full well what the Lazio Ultras and their fascist/neo-Nazi tendencies are about because that is where he, by his own admission, comes from. The idea that in saluting these openly neo-Nazi hooligans with a fascist/Nazi salute he was "just" saluting some notional "fluffy fascist" sub-section is laughable. He knows full well what the Lazio Ultras are and has repeatedly and publicly saluted them, even after he was made to attend a meeting with a Holocaust survivor as part of Lazio's/his agent's attempts to repair the damage caused by his salutes, while his manager said that "erm, yeah, the Ultras waving swastikas about is probably going a bit far", Di Canio made no comment on his beloved Ultras regular display of Nazi iconography but just said while he was opposed to the whole Jew-killing thing, the meeting hadn't changed his mind on his core beliefs. Might have been, had he had any misgivings about his mates waving swastikas, Totenkopfs, references to Auschwitz and Arkan etc to say "I'm more of a fluffy fascist lads, perhaps tone it down a bit on the murderous racist angle, eh?"
It doesn't really add up to the "Lib Dem wing of Fascism" picture he's (apparently quite successfully) spun to the international sports media while simultaneously keeping up the snarling fascist image for the lads back home does it?
It's a judgement call really which side of the fence you see it as sitting. He's clearly an endorser, and arguably active advocate, of Fascism. Which I'd kind of view as being a bad thing in it's own right. But there is no direct evidence that Di Canio personally endorses the Holocaust or the clearly neo-Nazi views of the peers he so warmly endorses. There's more than enough that any other public figure would be running a mile to distance themselves from if they weren't trying to tread a one face one way, one face the other line as he clearly is.
Bangkok Red has, quite cogently, argued that we should take his words ("I'm a fascist not a racist" and calling Mussolini "vile") at face value. I and Lumps and others feel that his actions (and lack of actions e.g. over not taking the very clear opportunity to condemn the display of swastikas at Lazio games as his manager did) speak far louder than soft spin dressed up for the foreign press.
And all of that is, to a large extent, an academic discussion of what lies in whatever the fuck passes for Di Canio's soul. Which, astonishing as it may seem, I don't give a fuck about really. What I do give a fuck about is the name and character of our club. Which if people could pull their heads out of the "How many points are we going to get next season?" sand would see will be very badly damaged by our association, and hence perceived endorsement, of a man like this.
As I've said repeatedly elsewhere, the same would apply if he was an open supporter (but not practitioner) of Al Qaeda or turned up to press conferences wearing a Pol Pot T-Shirt. Loads of people in seeking to ignore or downplay his open fascism and clear endorsement of neo-Nazi hooligans have tried to play the "Shouldn't bring politics into sport" line. I'd completely agree. Which is precisely why Di Canio is not a suitable candidate for our manager. Because he did. Not those of us who are objecting to him once he has done.