The story line is that Tyrrhenus wich was a Lydian, went to Italy with his people called Tyrrhenians.
The first Greek source to mention the Tyrrhenians is Hesiod, many centuries before Herodotus. Hesiod makes no mention of an eastern origin of the Tyrrhenians and places them exactly in central Italy close to the Latins. There is no other ancient source before Herodotus that associates the Tyrrhenians with the Lydians. Also for the Herodotus' story, the Tyrrhenians are those who are in Italy, not in Lydia.
As reported by Dionysius, Xantos of Lydia, the historian considered the highest authority in the history of the Lydians, makes no mention of Tyrrhenus as son of Atis, or of a Lydian colonization in Italy. As many scholars have pointed out, the Herodotus' story is based on false etymologies. It is not Herodotus' fault, since he reports what others had said.
In fact, according to Xantos of Lydia, Atis' sons were Lydus and Torebus and they, "having divided the kingdom they had inherited from their father, both remained in Asia, and from them the nations over which they reigned. (...)
"From Lydus are sprung the Lydians, and from Torebus the Torebians. There is little difference in their language and even now each nation scoffs at many words used by the other, even as do the Ionians and Dorians."
By mistake, Torebus and the Torebians have become Tyrrhenus and the Tyrrhenians. But Torebus and the Torebians were clearly not Tyrrhenus and the Tyrrhenians.
Xantos of Lydia reported by Dionysius:
"But Xanthus of Lydia, who was as well acquainted with ancient history as any man and who may be regarded as an authority second to none on the history of his own country, neither names Tyrrhenus in any part of his history as a ruler of the Lydians nor knows anything of the landing of a colony of Maeonians in Italy; nor does he make the least mention of Tyrrhenia as a Lydian colony, though he takes notice of several things of less importance. He says that Lydus and Torebus were the sons of Atys; that they, having divided the kingdom they had inherited from their father, both remained in Asia, and from them the nations over which they reigned received their names. His words are these: "From Lydus are sprung the Lydians, and from Torebus the Torebians. There is little difference in their language and even now each nation scoffs at many words used by the other, even as do the Ionians and Dorians."
The whole point of the hypothesis is the mythical or historical ( for modern pov ) pov of ancient greeks about Etruscans and the similar language of etruscans and lemnians. It's even wrote somewhere that the language of Lemnos was not Greek. The fact that Lydian language and Etruscan language are not similar is kinda clear, but it doesn't really mean anything, Neustrian Franks spoked Gallo-Roman and Austrasian Franks spoked Old Frankish, but they where all Franks. We are visualing an epoch ( -1200 / -1100 ) where ethnogenesis and indoeuropeanization were probably not complete. In the exemple of Pelasgians wich were probably not IE speaking peoples, would be related with peoples who are IE speaking peoples, because all people of a geographic area are related.
So you're basically turning the whole thing and claiming that the migration from Lydia to Etruria is the one that brought DNA from the steppes. Am I hearing you correctly? Really weird this ethnogenesis of the Etruscans, huh. By magic the Etruscans did not speak Lydian but another language, even pre-Indo-European, which at this point came from the sky.
There is not a single inscription found in Anatolia that resembles the Lemnian language and then there is the insurmountable problem that there is also the Rhaetian language spoken in the Alps that resembles the Etruscan language, and perhaps even the Camunic language. It is very unlikely that all these languages have come from Anatolia, when in Anatolia there is no inscription similar to these languages and when in Anatolia IE languages are attested long before in Europe, and when Pre-Indoeuropean ancestry constitutes the majority in southern Europe, and also in the rest of Europe remains a very important part.
Not to mention the fact, that archaeologically it is now widely demonstrated that the Etruscans do not differ from other peoples of pre-Roman Italy, and there is no evidence of the arrival of the Lydians, while there's evidence of contacts with the Mycenaeans.
Why would it be unlikely that Lydians lost memory??? This is highly speculative, has they already used Writing by this time. You make too much of a difference between Aegean World and Whole Anatolia, they might have been closer in ancestry and culture that with the most Central and Eastern Anatolians. If we should write ancient history only by the sole fragments that we have from the past, then we can wright everything and nothing.
If the Lydians are the among the first to learn to write, why then do the Etruscans learn to write only after the Greeks arrive in Italy? As soon as they arrived in Italy, did the Lydians unlearnt to write?
For the sake of precision, the Lydian language is attested long after the Etruscan language in Italy. It is the Luvian language, among the languages of the Anatolian family, which is the first to be attested using the Anatolian hieroglyphs, a script of which there is no trace in Italy.
I trust ancient authors way more than modern scientists, Colonial Rethoric doesn't equal Probably Made Up. It's just a POV that we can accept or refute.
I perfectly understand that legends have a greater influence on the public's opinion than specialist readings, also because legends are easier to understand, but this is your personal choice. You are obviously free to believe all the fairy tales you want, even in the historical existence of Santa Claus.
If we believe more in ancient authors, why not also believe in the ancient stories about the origins of other peoples? I think it is odd, to say the least, that only with the Etruscans is it believed that the ancient sources are true.
How notice the high prevalence of Aegean Ancestry in ancient Italy is not a clue about " mass migration " wich the mass part is not even needed in this case.
Can you show me where this paper speak of high prevalence of Aegean Ancestry in ancient Italy?
I prefer this answer of yours than the first one you made about Greek legends.
I appreciate it. It should be stressed that Greek legends have most likely nothing do to with the Sea People.