The only time I would consider hand brakes dangerous is when people have their brakes set so spongy or bad that you need to bring the lever all the way down to the bar to achieve good power, because you have to take *all* your fingers off the bar to get the lever down (I borrowed a friends bike that was like this once! and, his pads had glazed. fun!). Even half decently set up brakes don't get that way though, they have to be seriously neglected or poor.