Ex QF, not really sure what your point is - that's exactly what they do. Well, they may not openly advertise for tenders but they certainly go to hotels and say, "what's your deal for the following".
But it all comes down to price - what price Qantas is prepared to pay. And they will compromise on certain parts of that tender list, if necessary, to get the price down. Eg, you''ll get a pretty hotel all right, with a gym, but in a really dodgy part of town. Eg, Bonadventure.
Mate, years ago Qantas crew stayed at the Crowne Plaza Redondo Beach, but some non flying, "doesn't affect me" person calculated they could save $x mil per year so the crew were shuffled out. It was a brilliant location but "too good for crew."
Surprise, surprise, with accom at such a premium in LA, within a microsecond British Airways had stepped into the void created at Rendondo.
If Qantas was genuinely prepared to pay an appropriate price to ensure crews have a "home away from home" in a secure location, there'd be no problem. And I'm not advocating 5 stars, please note - just something that "equates" to a standard of living back home. That includes a safe location.