Early versions of Go outside of Google had no package manager to speak of and it _still_ has a relatively weird stdlib. It made assumptions about your development environment that largely were true at Google, but nowhere else.
The early gen garbage collector also wasn't really all that and had weird pauses that were difficult to debug. There was a nice enough concurrency model, but it wasn't earth shattering and it didn't solve any of the actual hard problems to speak of.
4/
Many of these issues have improved with time, but what happened next was a bunch of exec types LOVED golang. They could read it easily. They saw it as The Future™.
I was told repeatedly by multiple exec-types that this would displace Java and C++. That this would integrate better with the world. That it would come with a free pony.
This built a lot of resentment in engineers who had to deal with the execs telling them "THIS IS WHAT WE ARE DOING NOW" on the one hand and reality on the other 5/