You are vastly overestimating the technical abilities of the average QA person. "Just as easily spinning up their own VM with the Vagrantfile" assumes a significant base understanding of a lot of technologies.
I think you are vastly underestimating their abilities. You install git, virtual box, and vagrant. Clone the repo and type vagrant up. If they've never done it they can refer to the wiki page you typed up for everybody. I know every QA person at my workplace could easily do it.
I've found there's a broad categorization talent/skills in QA, but a lot of it boils down to this separation -> Able to do development related tasks (set up their own envs, run different versions of apps, etc.) or not.
Anecdotally, it also seems to correlate with how useful Developers usually find their peers.