I think that kings ought to be philosophers, metaphorically speaking: I trust politicians who prove they have at least some understanding of philosophical inquiry much more than I trust the ones who are skeptical. But philosophers themselves shouldn't be kings: hell, how would you pick the one to rule over the rest of them? The best philosophers are frequently the most controversial: the controversy surrounds them because of how challenging and provocative their thoughts are.
Here's the thing with "provably true" that I find worrisome: the process of proving something as rigorously as scientific research demands it is so slow, so painstaking, that if we relied entirely on science to inform our knowledge, we'd lose out on literal millennia of human experience. Now, there are some things for which scientific rigor is absolutely necessary: don't get me wrong, I think science is one of the best things ever. But it's not enough. It's a tool in an arsenal which employs many different techniques to get at knowledge, and as far as techniques go, it's a highly specialized one.
Philosophy is a much, much broader technique; in fact, it specializes in finding ways to look at even broader questions in exquisite detail. That makes it a very impractical tool if you're trying to, say, build a space ship. But it makes it a far more useful tool if you're trying to understand things as complex and abstract and subtle as, say, questions of how we acquire knowledge, or what it means to think. "Meaning" is something which science deals with very practically, and as a result its meaning will usually go only as deep as is needed to achieve a practical result. Once science begins worrying about satisfying deeper curiosities, well, it's no longer practical and your argument is moot.
You think philosophy is provably dangerous. Well, I think that science left unchecked is dangerous as well – it's such a powerful method of inquiry that it can convince you it's the only sort of inquiry that has any meaning whatsoever, which is a seductive promise (it's so simple! it could explain everything!) but not a true one. There have been certain controversies involving very bright scientific minds saying some very stupid things, and then attempting to "prove" that there's a scientific justification for what they're saying. It's especially frustrating because these scientific thinkers, who are so humble and questioning when examining the universe from their lens, are incapable of the same humility when offered any other perspective on their thoughts – even well-reasoned and meaningful ones.
But I wouldn't argue that because of this, we ought to cut funding to science, or insist that science change its techniques. No: science should do what it's good at, period. But so should philosophy. And so should mathematics, or theology, or history, or whichever other method of inquiry might yield useful and important breakthroughs. The dangerous part of science is its claim that it ought to dominate other fields of study, which practically speaking I find no different from the claim made by fundamentalist Christians that their religion should dominate all fields of study. There's a similar belief that their worldview is so right, so all-pervasive, that no other argument could possibly suffice to dethrone it.