Passive sonar is done extensively in the US Navy, I believe, because for a long time they had an acoustical superiority over their main prey - Russians. Most of the time you get to hear them, so why let them know you are hearing them?
If you have aren't sure of an acoustic advantage, your use of active will go up, hoping to create a less penetrable "buffer zone" - even if you tell the target where you are, hopefully it is harder for him to get within X miles, so at least you have some space to play with when he attacks.
With subs inching closer and through the background noise level of the ocean, active searching (not just occasional rangefinding) will become more common. You can play games with signal processing for awhile, but eventually there's just no signal that stands out above the randomness. At that point what's left is to hit your own sound waves into the water.
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