It seems like a superficial tabs-versus-spaces kind of point, but when you see how the standard library is organized and how package names interact with actual programs, you grok why underscores make people wince; "foo_bar" should either be "foo/bar", or just plain "bar".
The import statement at the top of the file can clarify what the origin of a package is, but in the program body itself, the package name should make the library feel as natural as "fmt" or "io" or "math".
The import statement at the top of the file can clarify what the origin of a package is, but in the program body itself, the package name should make the library feel as natural as "fmt" or "io" or "math".