This trope is getting old. Variations include "Go is only popular because Google spends millions marketing it!". There is a small team at Google that work on the language along with the open source community. I'm pretty sure none of Google's marketing team works to promote the language, and I'm sure that its success is much less important to Google than Erlang's success was to Ericcson. I don't know very much about Ericcson, but it wouldn't surprise me to find out they spent many times the amount on Erlang that Google spends on Go.
There are probably lots of reasons why Go is successful, but I'm positive that it has more to do with simplicity, learning curve, tooling, ecosystem, etc than it does with corporate sponsorship or marketing.