Let me introduce you to some programmers I have had to clean up after. Any language can be made into an inefficient pile of shit. I'm sure you've seen the same.

That said, I agree with your point they aren't using Golang widely, and it looks like from the job ads they primarily use node.js and are moving towards Golang. I have no real hard facts for that other than just reading the job ads (if you click their name in the link above it shows many open positions).