My view on this was that it has been claimed that the Goths derive their name from a root for rushing water, which I believe I read in Bennett's intro to Gothic book, along with one or two interpretations of the Cantilena. But if what this new dissertation is claiming about the location of the Goths' origin, then the issue of flooding is seemingly a non-issue. Instead, although I haven't read the dissertation, it seems as though it's possible that they named a geographical feature after themselves. I don't know if this happened, nor do I claim it did, I was just impressed by the fact that it seems possible. I see my name listed on some of the messages I post, and my username listed on the others.
People generally do decide on a name for themselves, even if that name just means 'people'.
And later on in time, they start naming things after themself. Hudson River is named after a person. America was given a new name despite what the natives may have called their surrounding lands, whereas Canada was basically given the local name, within reason. Bertil Haggman Anon. All rights reserved.