So of course there's a language angle. Could the Etruscans be from elsewhere?
One hint of such an origin is that the Etruscan language, which survives in thousands of inscriptions, appears not to be Indo-European, the language family that started to sweep across Europe sometime after 8,500 years ago, developing into Latin, English and many other tongues. Another hint is the occurrence of inscriptions in a language apparently related to Etruscan on Lemnos, a Greek island just off the coast of Turkey. But whether Lemnian is the parent language of Etruscan, or the other way around, is not yet clear, said Rex Wallace, an expert on Etruscan linguistics at the University of Massachusetts.Wait, what? The fact that Etruscan looks non-IE hints that they were immigrants to Europe? And the fact that related-looking inscriptions are on found a Greek island supports that? Sure, these things are not inconsistent with immigration, but judging from these points alone, we could equally well argue that these are the last remnants of pre-IE languages (cf. Basque, Pictish, etc.) I'm by no means pushing that view, please understand, but simply trying to point out that there's no probative evidence here.
From what I know, Rex Wallace is probably the best specialist in the ancient languages of Italy working today, and one of our best historical linguists. So, it's hard to imagine his view was captured precisely in that last sentence of the passage above: It is possible that these inscriptions and languages have a colonial relationship, that is, that one community sent immigrants forth who founded the other one. And if so, that could easily be described as a parental connection. But those are hardly the only options, and I'm not sure they are even the most likely here: These languages could easily be sisters, two communities founded by immigrants from a single source area. (That would fit fine with Herodotus's brief mention of their origins, I think.) Or more distantly connected cousins of some linguistic diaspora in the ancient world. It's like finding English spoken in Los Angeles and in Singapore and trying to figure out which one descended from the other.
Will the coverage of linguistic issues ever improve?
Image from Ancient Scripts, a site worth a visit.