A small side note: Scala has several great features, but "low development overhead" just isn't one of them. Also why so harsh on Go?
As for Go, I'd say that's the most honest description of the language I've seen in a while.
Scala is pretty good in the low boilerplate department. I'm not a fan of Scala in the slightest, but in terms of code more or less directly expressing ideas it isn't bad.
Scala certainly doesn't have high development overhead either. Build system more or less just works, plenty of libraries, minimal ceremony to do much. Don't get me wrong, I kinda hate Scala¹, but compared to _many_ languages it does have low development overhead.
¹ Disclaimer: haven't used Scala since 2.8. Maybe it's better now. Don't get your panties in a wad, but Scala is basically really shitty OCaml on the JVM in my mind.
I wouldn't want to go back to 2.8 even if people paid me a ton of money.
I love ML, but think OCaml is a poor ML. That's why I love Scala. It's extremely consistent, and design decisions are very considerate.
It's an amazing language and I can express my intentions much better than in OCaml (no typeclasses, no higher-kinded types, etc.).
Thankfully I'm no longer working with the JVM, so I doubt I'll use it much, but it could be fun to take another look at.
Oh, and OCaml is possibly getting typeclasses (via modular implicits—not unlike Scala actually, for better or worse). It's not very painful if you use an alternate standard library (i.e. Core) that actually takes advantage of OCaml's amazing module system.