Actually, to me it doesn't That just means it's easier to reach every computer behind your firewall if they reach that page. If I need to reach a computer through SSH behind my LAN but it doesn't have a port opened for it I just do ssh -A -t firstname.lastname@example.org ssh -A email@example.com
It does allow you to setup auth for even seeing the page. And you are still using ssh. Not sure why one system would be more vulnerable using ssh than another unless you are using weak passwords or outdated software on that system.
I don't need fancy stuff. I just like ability to have cli in the web gui. That is enough for me. Port 10000(webmin) and port 22(ssh) cannot be used outside of my LAN's subnet. I only have 3 ports open on my router:
It is mainly a cli but does allow you have more than one terminal open if you want. You don't need port 22 open on your router to use it. My biggest draw to it is that it is maintained.