It is the only industry I can think of where new hires must start at the bottom, regardless of their experience or previous rank. Try that one in a hospital, software company, police force, or even the armed forces. Never happens
Funny enough it actually does, if you were a Sgt with the NSW police service and wanted to move to QLD you would have to do a new 'school' with the QPS and join as a Constable. If you leave a police force ias ANY rank you always have to return as a constable. So in QF speak that would be like a 744 skipper having to return to QF as a S/O! , so infact it does happen with other 'rank' and file occupations.
Airlines like DJ basically had 'accelerated' commands for a lot of the highly experienced F/Os from AN, a lot of those guys got commands over guys with hardly any hours but started before them, so I think to say that guys with no experience are getting commands over outsiders is a little bit of an overkill. Australia has always had a lot of highly experienced F/Os that would have had Commands years ago in any other part of the world. Cadets at QF are sidestepped for commands and F/O upgrades over more experienced DEC pilots despite 'seniority'.
Interesting you also state that the BAe146 isn't much of a jump to the 737/A320. When Ansett was around a lot of pilots struggled and failed command courses and lateral promotions on both of those a/c types and ended up back on the quadrapuff. Most that did make it stated it was a big jump. FMC was a big hurdle for a lot it seemed.
Sadly a lot of things in aviation aren't necessarily right, but it is what it is, and it is their(employers) train sets so to speak.