The truth is it depends on why you are getting turbulence and the altitude. Wake turbulence (when you're following the plane in front of you too closely) is very dangerous as it comes out of nowhere and if big enough can really screw up the plane and make it uncontrollable. Your average weather-related turbulence usually isn't too much of a worry as there are a ton of planes up there reporting potential bad areas and radar is usually pretty good at finding bad cells.

The bigger concern, in my opinion, is at what altitude the turbulence occurs. Low altitude turbulence can be tricky, for obvious reasons.