Why is it that version managers are always mentioned after the installation instructions?

As much as I want to put this on StackOverflow, I think this particular question fits better here.

I hope this doesn't sound too petty, but this is something that has always bothered me.

I've always wondered why the designers/developers of programming language websites don't just put version managers right next to the initial setup and installation instructions in their documentation instead of long after, and sometimes quite hidden in the side-notes.

Most people (I would assume at least) follow installation procedures line by line. That being the case, and the fact that you usually have to install the version managers first if you have a need for them; wouldn't it be more logical to bring the version managers to the user's awareness right around the same point in the documentation as the language's installation instructions?

In fact, Ruby is the only language I've ever installed that started the installation section with something like:

"some language" Installation Options:

• Stand Alone Installation Instructions
• Virtual Machine Installation
• Installation With A Version Manager

So, as stupid as this might sound, I've begun to wonder if there isn't some reason for this. Obviously, I'm not trying to excuse anybody for not thinking of version management up front, however considering that I almost always forget about version management when coming into a new language, I'd assume that it's at least sort of common to make that mistake.

So, is this one of those globally common bad design things? Is this even bad design or am I just being whiny? Or is there legitimate reasoning behind this, and if so - what? It seems far too common a practice for it to just be by accident. I mean, who writes up installation procedures, then adds version management instructions at the tail end and not think, "huh, maybe I should put this up at the top." ?