Giving your team more powerful tools should always be a positive. If you don't trust them not to do harmful things with them then you have bigger problems.
It doesn't feel like that's a strategy that worked especially well for Scala or C++. Go isn't the only language that removes powerful tools: all the strict functional languages do too!
The issues that Scala and C++ have are far beyond just "having generics". Classical (ML-style) generics are an incredibly simple feature, much more so than, say, built-in channels.
I'd say typeclasses, templates, and variance have, sure. Those are separate features from generics in my mind. (But you could reasonably lump them all together under the heading of "generics" and I won't argue too much.) :)
If you read my comment carefully, you'll see that I was not in fact saying that people were wrong to like Scala. I like C, but I don't get irritated when people point out its innumerable flaws.
If you read my comment carefully, you'll see that I was not in fact saying that you were saying that people were wrong to like Scala. I think it's the best language available today and I think that's as a direct result of it being willing to put powerful tools in the hands of its users; therefore "It doesn't feel like that's a strategy that worked especially well for Scala" is, in my view, simply wrong.
