According to the docs, there is a rule about support:
The only officially supported installs of Discourse are the Docker based beginner and advanced installs. We regret that we cannot support any other methods of installation.
If I’m not entirely mistaken, Discourse entirely uses OSS software like Ruby which are supposedly working alike on all operating systems. This rule basically doesn’t allow me - and a couple of companies and other users - to use Discourse at all although it would work flawlessly.
I only use FreeBSD and OpenBSD servers, and while I’m positive there would be not a single problem using Discourse right from the GitHub repository, the fact that the developers stated they won’t help me in case of issues (it’s a “we don’t want you to use Discourse with your server”, not a “Discourse will not work on your server”) prevents me from doing so.
I suggest you to lift the ban on sane operating systems just because they don’t support Docker or to provide alternative installation methods for *BSD and/or Windows servers.