Krauss is not alone in his blindly dismissive attitude concerning philosophy. There is also the case of Leonard Susskind.
Susskind is an accomplished theorist who has proposed changing the very nature of cosmological science in light of recent developments in String Theory. In his book The Cosmic Landscape, Susskind argued that physics must give up the ideal of predicting the nature of the one Universe we observe because String Theory can't make these kinds of predictions. It's a huge claim that draws upon a contentious idea known as the “anthropic principle.” Ironically Susskind does not exert much effort dealing with the deep and deeply philosophical objections to this perspective. Waving his hands, Susskind poo-poo's philosophy's perspective on his radical idea saying “Frankly, I would have preferred to avoid the Philosophical discourse the Anthropic Principle excites”. Yea, obviously.
Susskind and Krauss think they are channelling the great Richard Feynman in their dismissive attitudes toward philosophy. Richard Feynman was famously scornful of the philosophy of science. He thought it was immune to finding relevant results or making real progress. But the problem is that we aren't living in Richard Feynman's age of physics anymore. Something strange happened on the way to the modern intersection of cosmology and foundational physics. Some measure of philosophical sophistication seems helpful, if nothing else, in confronting this new landscape.