Coming back to this after eight years, I think our philosophical ideas might be just as human-specific as our ethics, but philosophical skills might be near universal :-)
Humans have an ability/urge to find simple approximations to things. Applying that to human decision-making leads to a big pile of approximations, some very specific (like “chocolate is usually nice”) and some more general (like “when I prefer A to B and B to C, that usually means I prefer A to C”). The most general ones are called “philosophy”. Their proportion in the pile is small, as expected. That leaves the question why there are any at all, but there’s an obvious answer: some of our mental features have multiple uses. For example, “wanting” is reused for wanting many different things, so it makes sense that an approximation to it would end up approximating many things. A creature with a different decision-making mechanism, but with the same ability/urge to simplify things, would also have philosophical skills but end up with a different set of philosophical ideas. Does that make sense?