Yeah, Jetsar is owned by Qantas.
The problem with saying other airlines can make up for Qantas is that they can't actually. Qantas has protected routes (as it is designated Australians official carrier) and protected gates at airports etc. Other airlines can't just use their gates etc.
Lol, Jetstar sent out an email this morning to all staff saying they were not affected by the strike and that it was only effective for Qantas as of 26 October 2011. So much for Qantas only deciding to ground the airline yesterday...
I know that Qantas has never had a fatal accident, although with the amount of serious accidents that have occurred recently it is only going to be a matter of time. I'm not sure when ANZ and SA last had serious incidents, although I don't think they have in recent times and I feel safe flying them.