> which means a lot of copy and paste

Again, I don't think Go is perfect but on my list of wants, generics are not in the top 5. Can you qualify "a lot" in a real project you've worked on? Because after writing a good chunk (over 50k lines) of Go code, I haven't felt the sting as much as I hear it complained about.

> the lack of idiomatic way to deal with dependencies(no defacto package manager

Again, is this really a big deal? There's plenty of options, and if you are shipping any-type of commercial product you are going to want to be vendoring your dependencies in-house anyway. In which case, depending on something like NPM/remote maven repos is not a viable options anyway.