For myself, frankly I do not mind harsh critiques but such one liner comments are not really helpful. A good critique should give a good explanation on what went wrong, what should be done to correct the pic, and other possible ways to improve the pic etc.
Like others said, certain one liners speak volumes. If the "flash is too harsh", what more do you want to say about the shot. The statement adequately describes a shortcoming. I don't think a lengthy explanation on how to use a flash is necessarily going to solve the problem at hand. And most of the time the setup of the shot is not explained, eg position of strobes, camera settings used etc... without such notes it would be impossible to give an accurate suggestion as to how corrections can be made.