I'll confess to a) being a lawyer, and b) knowing basically nothing about intellectual property law, as it's well outside my practice area.

We all know the story about about Suntour's 1964 patent on the slant-parallelogram derailleur, how Shimano waited decades for the patent to expire, then incorporate it into their early SIS systems, and eventually crushed Suntour and conquered the world.

So why does it seem like this sort of patent-related exclusivity didn't happen with other cycling technologies? Campy and Suntour both came out with indexing (though less successful) right after Shimano, and Campy introduced Ergos right after STI shifters. Bottom bracket interfaces, hub types, etc all seem to move across the industry in one big sweep now, across all the major manufacturers. What gives?