On one hand, I ran into this myself a couple of times (needed to spec some tolerances for shafts and holes; wanted to find laboratory glassware specs). Didn't end up getting them since it was a one-off query each time.

On the other, you have to admit that they do a much better job of making money for the value they provide, compared to e.g. compiler developers. (Just from a cold capitalistic viewpoint. I don't philosophically agree with not having a free way to get started with programming.)