A very informative presentation:
Go at Google: @ InfoQ
"Rob Pike explains how Google designed Go
to address major development issues they encounter while using other languages:
long build times, poor dependency management, lack of robustness, etc."
For example, Go programs build 40 times faster than equivalent C++ code!
The Go Programming Language course @ Pliralsight
Even curly brackets are preserved for a reason to keep it look "familiar"
The same reason is stated for JavaScript, as well as Java and C#.
This is to help developers transition from other programming languages.
But there is also a more practical engineering reason:
to avoid hard to detect semantic errors caused by changes in indentation,
observed when embedding Python language, also popular in Google, to other tools.
