To put it somewhat poetically, they freed us from the shackles of superstition. Do you think that neolithic man would have got around to building a steam engine if he'd just thought about it for long enough? Well here's the thing: he had fucking millennia and did fuck all.
But get this: a few hundred years after philosophy gets a grip (proper decent philosophy, empirical and logical and English-speaking) we have the internet and cancer treatment and liberal democracy and Sky+ boxes and the emancipation of women.
Do we get to blame philosophers for nuclear bombs, poverty and global warming as well then?
But seriously, a hunter-gatherer society is not going to start inventing the steam engine. It doesn't matter what they think. They can have whatever superstitions they like or the most marvelous enlightened philosophy (incidently why isn't a superstition a philosophy?). They are not going to invent the DVD player.
Perhaps philosophy and civilization/science/technology tend to occur together. Even more likely - its probably just that significant times tend to produce more striking philosophy. Philosophy as such is a constant.
The idea that philosophy produces great civilization is central to a lot of religious belief. Perhaps Islam is the most striking example of this. This is my concern here. Why are reasonable, enlightened people spouting religious clap-trap?
I want to get away from the idea that just because something is the foundation then it is of fundamental importance. A subject at the foundations of other subjects is really of less importance.