Some of the best, and a lot of the worst, accommodation I have ever stayed in were hostels in Australia. Despite this, safety, or lack of it, was never a factor in deciding which hostel to stay in.
The only time you do not have at least some information about where to stay is on the day that you get to Australia. Arriving at an airport, half asleep after a long-haul flight, all you want is a bed for the night.
Looking at the arrivals area accommodations board, the hostel with a freephone number and a free airport pick-up service is inevitably the one you call. You promise yourself that if it's a dump you'll find somewhere else tomorrow.
Availability (the most popular places are often booked out), location (close to public transport) and price are what you're most concerned with when phoning to book a bed in the next town on your itinerary.
Thinking about it now, I can remember only one hostel that had smoke alarms in the rooms, and the only places in which I saw fire extinguishers were kitchens.
The only time in a year that it ever occurred to me that a place may have been unsafe was in a hostel in Perth that had too many beds per room and corridors that were too narrow. I still stayed there for three nights because it was cheap and I met some nice people. I won't do that again.