Here's a joke I heard recently:
So this guy walks into an interview at a scenic bush operator and the chief pilot says: "I see you have 1000 hours now, how many of those were instructing?". The pilot responds: "800". "So you really only have 200 hours then", says the chief.
Seriously, there's a lot of prejudice everywhere in aviation. Having a few RA-Aus hours at the start of your career is likely the least of your worries...
The "only 750 RA-Aus hours for ATPL" is a joke. It would make sense if the rule was "only 750 hours in non-complex aircraft", but when you can do 750 hours in an RA-Aus Jabiru, then put the same jab on the VH register and do the other 750, clearly someone hasn't thought this through very well.