Why did it have to be better? It just had to be created and evangelized to a specific group (and likely because it was by a specific company). I don't think it has anything to do with "better" in one way or the other.

Developers are constantly looking for new languages to fiddle with without any objective reasoning.

Sure, they're looking for new languages to play with. They're not looking for new languages to write major projects in, though. You write major projects in languages that you have already fiddled in, and the fiddling has given you confidence that they're up to the task. Nobody (sane) sees a publicity blurb and decides to bet a major project on it.

Don't confuse "they came to a different conclusion than me" with "they're sheep".

I mean cargo culting tech and languages is practically a meme at this point in tech. I'm not sure I can scientifically argue that its widespread but I think it is equally futile to argue that it does not happen frequently.

Does it happen? Sure. More often than it should? Absolutely.

Often enough to account for the popularity of Go? I strongly doubt it. It could have accounted for Go's popularity in the first year or two. But now, Go has been used by too many people to do too many things. Go's popularity now is based on its ability to help you get things done, not on Google's name.

It didn't have to be better (since it isn't), it juset had to be backed and pushed by Google.