Bloggsie’s legitimate concern is the pilots with finger trouble who are not broadcasting on the correct frequency, or have the volume turned down and are not hearing anyone else’s broadcasts, or are geographically confused by 180 degrees or otherwise not where they say they think they are - unalerted see and avoid is probably less risky than being altered to traffic that isn’t where it says it is - assuming they say anything at all on the correct frequency. We don’t know what we don’t know, and sometimes what we do know turns out to be inaccurate. (Ask e.g. Dom James about it...) Mildura gets much, much busier than Broken Hill.
Nonetheless, the fact remains: CASA, Airservices and the management of the RPT operators have decided that the risks at Mildura are acceptable. ‘Dirt road’ airspace and the corresponding ATS provided in it are good enough for Bloggsie’s 100+ punters down the back.