There is
so much power in the wind. If you are a little late with feathering you might end up having too much momentum to be able to use a friction brake without burning it up. So a long period of steady wind followed immediately by an increase to the point where you can no longer stop the machine is quite risky: all that stands between you and certain destruction is either a lucky lull in the wind or your continued ability to feather it and that can get surprisingly hard when you are dealing with high winds. To the point that if you go 'coarse' at high RPM you end up pulling over the tower due to the extremely long arm for that force to take effect.
Never ever underestimate what the wind can do. Wind turbines will always have some latent risk (as do most other activities and constructs). For every design there is a pathological set of circumstances that should never happen. But once in a long while it does. What should surprise you is that so few of these accidents happen that they are news.