I'd like to point out that Mumble is one of those rare solutions that works just fine on the Tor network, for everyone's privacy. Why would it be normal for a voice server to know where you reside in order to take part in a discussion?
In the age of everything WebRTC that only works with JavaScript and countless invasive browser "standards", Mumble is very refreshing. (Yes you can technically tunnel WebRTC through Tor by using firefox/chromium instead of Tor Browser, but by doing so you will leak your IP!)
It's not so easy no, but it's not so hard either. You need to use a SOCKS5 proxy with localhost:9050 (where tor usually runs). Then you need to connect using TCP not UDP.
I believe it's as straightforward as that, but to be honest i haven't fired up a network log to check that Mumble wasn't sending IP addresses or other "private" information over there.
The average person's not going to know (or even want to know) how to do that.
It needs to be made as simple as a "connect over tor" button, and everything should be done for you, including setting up tor... anything requiring more interaction or knowledge is going to lose a lot of users.
Not that i disagree with your point, but that's not exactly part of tor's threat model that it would be setup by a random application trying to leverage it. Usually, you set it up once on your system then apps access it.
Auto-setup may be easier if you're targeting a certain platforms, for example on Android you can keep a local copy of the F-Droid PGP key, download the latest installer, set it up, and from there enable Guardian Project repository and setup Orbot (tor for Android). On Debian, you could just run "apt install tor" (acquiring privileges on the go) from your program and then start proxying through localhost:9050. But if you're targeting many systems the problem becomes hairier.
If you have better suggestions about how to ease this process, i'm sure folks from the Tor community will be very interested! :)
In the age of everything WebRTC that only works with JavaScript and countless invasive browser "standards", Mumble is very refreshing. (Yes you can technically tunnel WebRTC through Tor by using firefox/chromium instead of Tor Browser, but by doing so you will leak your IP!)