Since when? I run multiple apps on vagrant every day. That is pretty standard.

And most likely you are running those multiple apps on multiple VMs.

Well, a VM per sensible unit of configuration management the user is supposed to choose. An "app" is a very slippery concept.

Well, there is a big difference, but not the one you've managed to come up with. Vagrant is normally used to run full VMs (although you can use it to drive Docker), so while you might run App, Supporting App, PHP, Apache, Node, Nginx, MySQL, Mongodb, and Redis all as separate containers, you'd probably put them all on the same VM. Your comment almost makes it sound like you don't understand Vagrant or VMs.