No one has a problem with a haplogroup originating somewhere 30,000 years ago. The problem is, you keep deflecting the obvious, and keep referencing "but, but, my ancestor was already in Europe 30,000 years ago". That's called coping.....
We are not talking about a 30,000 year old ancestor that existed before documented history, as well as before the last 2 ice ages. In what world is any of that even relevant to discussion?
Most haplogroups, including Indo-European R1a and R1b, had no cultural or ethnolinguistic affiliation whatsoever. At least none we are aware of. Likely all dead languages and races anyways.
What we do know about your I2, Mr. Western Hunter Gatherer, is that you belong to I-Y1320, which, is a Y-DNA that is associated with Proto-Slavic/Slavic expansion. Your most recent ancestor had nothing to do historically with those guys 30,000 years ago. Sam as all R1 peoples were probably in Siberia, or Central Asia before Proto-Indo-European formed.
I have already mentioned the most likely form of transmission into Proto-Slavs/Slavs. Considering that the brother clade of Y3120 is only found in German, and a Frenchman of German origin, it is likely that (like Western related clades) Y3120 was part of some East Germanic extraction. Be that Bastarnae or Goths. It's absolute spread and representation is only found in Eastern Europe, and Southern Slavs as well as Albanians and Greeks who likely assimilated these Slavs or Goths. However, we do not have ancient East Germanic remains that are I-Y3120.
You have tried to claim on many forums, including Anthrogenica, that R1a is the only Slavic haplogroups and I2 is WHG. Clearly ignoring the fact that we actually have Celtic and Germanic remains with R1a-M458, and even R1a-Z280, and yet zero I-Y3120 thus far. While it is likely to be found on them given the distribution of modern distant cousin branches to I-Y1320; you clearly like to deflect this fact in favor of your WHG argument, when its not relevant to the branch we are discussing.
Using your logic, R1a is not Baltic(Z280), its not Slavic(M458), its not Germanic(L664), it's not Scandinavian(Z284), it's not Satem Indo-European(M417/Z645), it's not Siberian (R -Malta Boy), it's Alien at this point 30,000 years ago.
So please, enough ignorance from you. Get with the program, and either speak in terms of documented and recorded history, or just crawl back into your WHG cave and pretend you live 30,000 years ago.
For some reason you continue with this anger, I am stating facts that I2 was born in Europe 30,000 years ago. Why should someone ignore that history, next you will tell me that R1a is not common in India and Turkic people because you want to ignore the history of the line.
But at least finally you are understanding that the Slavs picked this up somewhere. I think around North Europe, maybe from the Suebi/Suevi.