At small to medium sized companies it isn't uncommon to host a number of self-hosted services, such as GitLab, MatterMost, some wiki, perhaps OwnCloud, the list goes on. Securing all these services takes some non-trivial effort, even if you manage to get all services talking to your local LDAP server (we did!). Only recently GitLab advised users of the self-hosted solution to upgrade ASAP due to a security issue.
To cut ourselves some slack, we placed all these services behind an Nginx proxy. That proxy is secured with client-side TLS certificates. So if you try to access https://chat.example.com without it, you just get a friendly error message (actually, you get a picture of Grumpy Cat saying 'no', but you get the idea). With certificate, you get the service you wanted to access. You still need to log on with the service, but that's usually just a matter of doing it once and ticking the 'remember me' checkbox or something similar. For our users it just works.
Generating new certificates and revoking old ones is fairly simple for the administrators (couple of scripts, ample documentation).
The arguments against public use still stand of course, but for this scenario it is a great solution.