I think Googles stamp gives it some legitimacy, but I think the much likelier explanation is that the values in Go and its design speak to frustrations a lot of people actually have. This thread is full of people arguing in favor of gos error handling. You can dismiss them all as cranks or sheep if you want, but I think that would be misunderstanding something.
None of these things were technically bankrupt (including Go), but their adoption curve would not have been what they have been without Googles name on it.
There's likely other OSS that's technically better, but did not have the network effects google-backed software had from day 1.
Assuredly not C++, nor Rust... No javascript, swift has become more complex apparently, not haskell... Not C... OCaml? No it has a weird syntax, French people and wanting to be different... Etc...
So no, Go has genuinely appreciable qualities that are not found anywhere else :o)
To me, there were a lot of obvious reasons to choose Go in a corporate environment where my success is graded on my ability to deliver and the quality of what I deliver.
For every popular Google project you read about there are many flops, including ones they appear to develop in spite of.
I suspect it's a bit more than the Google stamp of approval - the innate simplicity of the language is attractive, it has almost Python-like simplicity without the performance concerns, and it has a "one true way" approach to formatting that settles any bikeshedding arguments in dev teams.
It's not my personal favourite language - the poor error handling discussed in this thread, the mess of the package management system (I mean, Python has a mess of a package management system, but that's more forgivable in a language from the 1990s, not the 2010s), the lack of decent standard library collections, etc. But I can see the appeal.