It depends on what you consider failure. If you feel popularity is the main metric then golang is successful. Outside of that metric golang is pretty bad.

The proof is in the pudding. Here’s a quote from rob pike the creator of golang:

“The key point here is our programmers are Googlers, they’re not researchers. They’re typically, fairly young, fresh out of school, probably learned Java, maybe learned C or C++, probably learned Python. They’re not capable of understanding a brilliant language but we want to use them to build good software. So, the language that we give them has to be easy for them to understand and easy to adopt.”

Basically in a nutshell he’s saying they dumbed down golang so it’s useable by beginners. Golang is a step backwards. A failure in language development but a success in popularity.

You dumb down a language to a point where the language is so dumbed down it hits the largest demographic. You are part of that demographic. It’s similar to the demographic that voted for trump because he’s not fakeish like all the other candidates.