Well a rejection letter is never easy to take, whatever the reason.
But be reassured: yes there's a big difference between jets and turbo-props. JETS ARE MUCH EASIER! And the simulator is an ideal place (and far more accurate place) to find out how a pilot works as a crew member and potential commander. I'd back actual practice vs. psych testing any day.
It has always seemed weird to me that Qantas (and AIPA) are happy to reap the rewards of selling seats on any aircraft with the White Rat on the tail, implicitly telling the punters that the whole thing has the QF seal of approval....but in fact there's an apartheid system operating as far as the pilots go with "separate development" being the ongoing order of the day.
Do QF really want to explain to the SLF that the Captain who flew them on their Dash 8 isn't really Qantas material?
I can't recall total numbers etc but my recollection is that TAA incorporated pretty much all of the ex-AQ pilots without too many problems. I might be wrong of course, but giving the ex DC-3 people a shot at it was alt least humane. Of course that was in a more enlightened time under real airline management.