In any case, designing and even implementing a PL better than Go is not a particularly hard thing to do. Making it popular in this day and age, on the other hand, generally requires a large corporation backing you.
"It's because people who like Go are stupid and companies need stupid people to write stupid code" may have made you feel smug and secure during the last 15 years, but what about the next 15? Or the 15 after that? Are you still going to be complaining about the stupid 70 year old wheel made by that dumb guy Pike that you hate so much?
Argument from success disregards the simple fact that, in this day and age, no language succeeds without massive corporate backing - and, conversely, a large corporation can throw money at a language to prop it up in a situation where it would struggle to get market share otherwise. So, no, the fact that Go is as popular as it is, is not particularly interesting. If it actually overtook Java - its most direct spiritual competitor - then yeah, I'd consider that a more serious data point.
> There are already many better languages out there.
Not really. Even if you're just looking for a reasonably productive mainstream language with effortless native, static compilation Go is likely the only language that fits the bill.