What's up with not providing Archlinux?
The title says it all. Your job is to provide infrastructure (a VM) on which we should be free to run whatever OS we want.
Why can't I provide a custom ISO to boot the droplet from and continue the installation, or better, why can't I log into a recovery shell from which I can mount the / partition and install whatever I want?
Linode provides Arch by default and allows you to access a recovery shell from which you can install whatever you want by mounting the root partition and copying the files manually.