This thread has produced some interesting commentary around whether philosophers actually want to answer their own questions, or whether they enjoy sounding profound by debating big questions but don't want to lose that opportunity for profundity by finding single correct answers to them.
I don't quite disagree with the latter theory: the main reason I quit academic philosophy was exasperation that people were still debating questions where the right answer seemed obvious to me (like theism vs. atheism, or whether there was a universally compelling morality/aesthetics of pure reason), and worry that my philosophical career would involve continuing to debate these issues ad nauseum rather than helping to solve them and move on to the next problem.
But when I explained this to a particularly sarcastic friend, he summarized it as "So you think philosophy is useless because not everyone agrees with you?"
The problem isn't that philosophers never come up with solutions. The problem is that they come up with too many different solutions.
Science has solved many scientific problems, and anyone wondering what the solution is can look it up in a book or on Wikipedia. Philosophers have also solved many philosophical problems, but it is full of so many distractions and false solutions that anyone wondering which proposed solution is correct will have to become nearly as good a philosopher as the person who solved it in the first place. It's much easier for science to settle its disputes via experiment than for philosophy to settle its disputes via debate.
I am wary of criticizing the discipline of philosophy simply on the grounds that not everyone in it agrees with me. But I also don't want to let it off and say it's okay that they've managed to go so long without coming to any answers, when it seems to me that settling at least some of the easier problems is not that difficult.
How do we tell the difference between a discipline that doesn't really seek answers and a discipline which honestly seeks answers but just can't agree within itself? And how can philosophy do something about its level of internal disagreement without having to apply the "kick out everyone who disagrees with Less Wrong" solution?
I'm not sure what you're worried about. Just as you can't force people to move on from a problem that you think has been solved, so too they can't force you to wait while they work it out.
In the early modern period various thinkers were asking questions that would ultimately lead to the foundations of modern science (I'm thinking of Francis Bacon, Rene Descartes, John Locke and others). Philosophers have continued worrying about a lot of these issues (problem of induction, demarcation) while the scientists have moved on and made many fruitful discoveries. You may think that this shows that the philosophers have wasted their time, but so what? It hasn't slowed science down. It has also proved to be important. When new discoveries (particularly in physics) question the underlying assumptions, or where the method seems inadequate for solving the problem, then it turns out to be rather useful that there are some philosophers still thinking about these things.
So, you are free to carry on with your assumptions, and ignore others who think the matter is not solved, but further down the line you might be grateful that others were a bit more hesitant.
Indeed, much of what we think of as "modern science" used to be called "natural philosophy". Even "logic" used to be considered the realm of philosophers rather than mathematicians. Philosophy may be maligned in part due to a linguistic selection bias where, as soon as we start to really understand a subject, we stop calling it "philosophy".