I guess it depends largely on what philosophy you're considering, as obviously it's far too rich a subject to be dismissed out of hand entirely. The problems probably stem from the point that often philosophers take aspects of physics that either they don't understand properly, or are already recognised as obsolete or not the complete picture, but then try to build a philosophical model of the Universe anyway. Inevitably, such philosophers are going to reach dodgy conclusions.
This perhaps explains why I'm dismissive of Jackdaw's "thinking outside the box" comment. Philosophers are probably better at this in theory than physicists are really, but the catch is that their "box" idea of the Universe is often rather a lot smaller than the physicists' one is. A philosopher's typical box, until recently at least, has been based on Newtonian-like physics, which is 300 years or so out of date. Our physical understanding of the Universe has moved on, and many philosophers have to do a lot of catch-up still. When they do, some of the philosophical result may well be useful.