I think, the most valuable skill for a developer or project manager is to learn to throw stuff out.
I now work with a guy who's a major code hoarder, and whom I fight tooth and nail for every piece of shit in the repository, regardless if it's referenced elsewhere or not.
And some of this shit is not just dangerous, but outright flammable. I found 148 unescaped SQL selects over the whole project.
At this point "being hacked" is less of a "cybercrime" and more like a "natural selection" sort of thing. Like leaving your password on a post-it note on your desk or something.
By the way, what I respect about Go - is that it strives to exclude the situation where you have unreferenced entities. If you're gonna import a lib, or declare a variable, or whatever else, you MUST use it somewhere down the line, otherwise the project just wouldn't build.
I love it when the tools are built in such ways that they shape good habits. Mandatory indentation is one of the reasons I loved Python so much.