I'm kind of with you about Google being heavily responsible to the level of which Go became an success, but that has been the case (backed by large companies) for many popular programming languages such as C, C++, Java, Rust, etc... It helps, but not every corporate backed language is successful or makes it to the top 20.
I don't completely buy the argument that a Google backed Haskell would have been as popular as Go. Readability (which is subjective), familiarity (often C is the reference), and the ease of which the language can be learned are still major factors in widespread acceptance.