Crab,
I'm surprised, that you are surprised! I can't think of a standard civvie VHF radio that is set up to monitor guard, nor anyone who does so as a matter of routine. The airlines tend to keep their third VHF on 121.5, but it gets misused as a result; almost like "Crab Common"
Most commercial GA helicopters would have 2 VHF's, but the second is more likely to be on a company frequency than on 121.5.
With Australia slowly dragging itself into the late 20th Century for airspace management, we're finding the issue of communication more of a problem. Last year some bright spark in Airservices Australia actually
removed all the frequencies from VFR charts, because he/she/it decided that non IFR aircraft didn't need to know area frequencies as it would then clutter up the airwaves
