I think at least one of us does not understand.
Some other torrent clients encourage us to password-protect access to the client,
so that in the event of being hacked, one's torrent facility is more difficult to put to nefarious (and potentially embarrassing) unauthorised use.
Fair enough, this option is often so obscure & difficult to find that many of us are unaware we should be doing that, and may let it slide!
From what I can see, Tixi provides no ability to password-protect itself.
From a security point of view, that's B- poor.
It might also indicate a dev. mindset that security is an unimportant tack-on to the main event {yes, some people still believe that, even in this day & age}.
I'm in the camp that says security can be a pain, but, like not leaving one's front door open, is probably a necessary precaution.