Go's very lack of expressive power is what helps make it an enterprise language. It's simple enough and limiting enough so that a non-brilliant developer has little trouble picking it up, and is unlikely to run into a complicated corner case. As statistics inevitably have it, half the developers are below median level, by definition.

The really smart stuff in Go, like goroutines scheduling or lightning-fast GC, is all under the hood, and you don't get to touch it, and don't have to.

You can see the same pattern in other wildly successful languages of the past, such as Fortran, Cobol, Visual Basic, or PHP.

Having one of the largest IT corporations backing the language and actively using it does help, too. But I would not exaggerate this factor: Python got to the top without a comparable corporate support from its creators.