The article seems to make a lot of very dubious claims about Java. Especially when they started this project, Java performance was much better than go (Those double-digit second GC pauses weren't a concern with go?), and the Java garbage collection remains much more sophisticated than even current bleeding edge go.

Also the claim that you have to add extra interfaces to Java is completely false. There's no reason at all you need to add pointless interfaces in Java. Java's type system is strictly more powerful than go's type system. This was actually a design choice in go to make the language easier.

Java generics are also a huge boon when writing something like a database.

Modern C++ also would have been an excellent choice for writing a database, and would have been much more productive than go.