I don't know if that disproves that Go was intended to solve Google's problems, though. I think from the early writings of the authors of the language in its infancy, it was pretty clear that they intended it to solve problems they were having at Google (i.e. the single-pass compilation design was intended to help with the compilation of their gigantic codebase). If it hasn't gained traction at Google, that only proves that it failed to solve a lot of Google's problems.
That's still not to say it's a failure in an absolute sense: it may have solved the problems it was intended to solve.
I don't know if that disproves that Go was intended to solve Google's problems, though. I think from the early writings of the authors of the language in its infancy, it was pretty clear that they intended it to solve problems they were having at Google (i.e. the single-pass compilation design was intended to help with the compilation of their gigantic codebase). If it hasn't gained traction at Google, that only proves that it failed to solve a lot of Google's problems.
That's still not to say it's a failure in an absolute sense: it may have solved the problems it was intended to solve.