Maybe you haven't seen that version of the story too much because it's a bunch of nonsense. Trying to say the Jews somehow brought their slaughter upon themselves is the same trash talk that's been going on for centuries. The Jews were kicked out of country after country, exploited, forced to leave without property, forbidden to own land or be in guilds in parts of Europe, and in the case of the Crusades, forced to convert or die, then becoming the focus of rage when their conversions were deemed phony (and you'd think the sword would convince them that Christianity was the best religion.) It was all so twisted and shameful. Best to face the truth of history and move on to the present day.
I'm sorry, but the historical details I mentioned are true. I'm not saying that the Jews deserved to get kicked out of Spain. I'm saying that they got caught in the middle of a war to the death between the Spanish and the Moors.
It was by no means evident at the time which side would win that war. Constantinople fell in 1453, the Siege of Vienna was in 1529, when it looked as if all of Europe might be lost to the Turks, the Battle of Lepanto was in 1571, and it was not until then or even later that Christian Europe won naval superiority in the Mediterranean. Perhaps the Spanish were entirely wrong to expel the Jews, but that was their basic reason.
You state in your first sentence that that Cicero's version was rare because it was nonsense. To cavalierly dismiss something that may contain some truths could make it much more likely that the same type of pain,thievery,ill treatment and worse will occur again.
There were a variety of factors involved in the decision to expel the Jews. Isabel and Ferdinand had many Jews in their Court; these were both Jews who had converted to Christianity and those who had not. Many of the leading lights of the Church - important bishops and even Cardinals - were converted Jews. However,there was considerable anti-Jewish sentiment among the people, probably stirred up by jealousy on the part of the barons and petty nobility, who did not like the prominence that Jews had achieved or their relative financial well-being (since Jews did not live by farming but by skilled artisanry or by finance or even, in some cases, by "knowledge work" - translators, physicians, etc.). There were riots and attacks on the calls (or semi-autonomous Jewish areas in Spanish cities). Finally, when Isabel decided that the Spanish Crown did not have the resources to protect the Jewish residents anymore, she ordered that they leave. Of course, she also ordered that they surrender most of their wealth to the state when they left, since the Spanish crown was aggressively seeking income to fund its project of unifying Spain, which was one of the sources of its conflicts with the barons, as well.
There was some feeling that the Jews were supporters of the Muslims, at least as far as lending them money for arms, etc., but this was simply another part of the anti-Jewish feeling that had been building among the jealous nobles and civil officials even prior to the victory over the Muslims. Incidentally, if you think Spain is bad, remember that most of Northern Europe didn't even have Jews; England, for example, had expelled its Jews centuries before, in 1290, after years of increasing restrictions and attacks.
In other words, it's a very complex history. The perception that the Jews supported the Muslims may have had something to do with some attacks on them, but a lot of it was much more complicated than that and had more to do with politics and the economic situation than with anything else. In any culture, Jews, who were at that time always perceived as foreigners but at the same time did not have the power of a foreign government behind them, were an easy target for any popular frustrations, fears and resentments.
Let's not pretend that the Jews are nothing but paragons of virtue that did nothing but mind their own business, their own prophets were pretty harsh in condemning them. The poor innocent victim simply doesn't apply to any group of people. Like the stories of how native Americans were simply a bunch of pacifistic environmentalists...