Well, mine is accessed through an internal staircase, so it's really no more dangerous than walking upstairs from my living area to the bedroom. (Aside from the fact that I'm more likely to be drinking on the deck than in the bedroom.)
Second apt I looked at in SanFo had a deck. I walked out to check out the view and glanced down to spot a naked guy with spread legs tanning.
Maybe it's a good thing there are few roof decks.