While this is technically true, it's important to note that it's not usually desired. You should be running a fairly recent version to keep up with patches or

While this is technically true, it's important to note that it's not usually desired. You should be running a fairly recent version to keep up with patches or match your server, you should be running RVM so you can keep a gemset and use bundler, and you should use homebrew to make installing other packages easier. Not that any of that is difficult, and you're right to a degree: you can get started learning using one command and go from there. It's really not that complicated.