What annoys me about a lot of tech blog posts like this one is that they're essentially voodoo. People like the author write instructions about what you should do without even understanding the instructions themselves.

    "I’m not entirely sure what the filetype lines do. I’ve read that they’re necessary and so far I haven’t had problems."

His example .vimrc has filetype listed twice, which is redundant. This in itself isn't a big deal, but the problem these lines illustrate is.

Sentences like these are the reason for billions of blog posts about setting up an OpenSSL certificate authority all repeating the same example which the documentation explicitly mentions is the wrong way of doing things.

In fact I find that these voodoo instructions often crowd out any actual proper tech guides in the search results, all for the sake of drawing traffic to some blog...

Don't write tech guides if you can't be bothered to do the research and explain to your readers why they should do what you do and what exactly they're doing!