Like all generalisations, the hurt is in the detail. Not such a simple matter, I fear ... consider turbulence, for instance, and whatever get up and go you may have thought you had has just got up and gone ....
The main protection is that we don't have very many critical flight phase failures .. it is always most important to keep in mind very firmly the fact that the book data is based on reasonably good conditions .. turbulence, shear, inversions, speed control etc., for OEI climb are the killers ...