If you can't do it on desktop, you can't do it at all. Mainly because some of us have real work to do.

If the only "usable" implementation is on a hard-to-physically-secure mobile device that uses a tonne of different uncontrolled network access points a day -- that's not really an option now, is it?

I feel you're missing open whisper systems' target audience. If you've seen how regular people use computers, their phone is the most secure device a normal person owns. Not the most secure if you're worried about targeted attack, but the best place to put a dent in cheap dragnet surveillance :)

You won’t have that until someone takes the time to produce such a client.