Go's main attraction there is that it's a simple, script-like language that compiles to easily deployed static binaries. That enables people who's main job is not necessarily coding, but with a good scripting background to solve problems by writing more complex/performance-critical stuff which was previously not feasible in languages like Python, Ruby, ...
These projects requiring more performance would have required a seasoned dedicated C/C++ coder before, but now they can be started and maintainer by people initially not focusing on programming, but on solving problems they are facing in their daily job. They don't have the time to invest learning a language with complex typesystems where initially, you'll be fighting the language itself more than solving actual problems. For programmers, this investment is useful, it's their main skill and is worth something. Ops people have other things to worry about, and just want to solve problems.
It does mean wheels are being reinvented, but the major projects now have pretty smart people working on them, hitting the limits of the language and it's garbage collector, pushing them forward.