You know, the more I think about it, I don't know that only criticizing is necessarily a bad thing. I suppose it depends on what you mean by criticizing and what, exactly, is being "criticized." Let's take Nietzsche. Nietzsche was a destroyer and the most scathing critic of all time. In fact, he called himself the "annihilator par excellence." Nietzsche criticized the shit out of Christianity, among other things, and essentially destroyed it. Should he have held his tongue because he had nothing to replace it with? I say no. What he did was monumental enough and worth his time and energy. It would be too much to ask of one man that he also come up with something to fill the void now left. Don't get me wrong, it would be IDEAL and preferrable to destroy and then create something to fill in the void. But it would have been worse had Nietzsche not said anything at all. Evolution moves slowly, philosophers build off of each other. Nietzsche destroyed so that someone after him will be able to create.