If the company tell me to fly from A to B and it's operationally safe ( as in this case ) then of course I'd go, who wouldn't?
I wouldn't. Operations staff are there in a support role and even though they are well trained, they generally haven't experienced operations at the coalface. Pilots (especially Captains) have traditionally been paid well, not just because of their flying skills but because of their experience and management skills. We are paid to make these decisions - with advice from other specialists. If you let these decisions be made by other staff then you are endorsing Jetstar's low salaries - they are simply paying you to be a pilot, not a Captain.
It's their a/c after all.
And it's your licence.
In Australia, you may get away with just a fine, but try doing this in another country and you could end up in jail for a considerable time.