I believe the story was (at one point at least) that RPi used a Broadcom SoC that had already been developed for some other application, keeping the cost down b

I believe the story was (at one point at least) that RPi used a Broadcom SoC that had already been developed for some other application, keeping the cost down by using a chip that was already in volume production. I don't believe this is still the case but then again I haven't been following RPi development very closely. I don't think it indicates any use of inferior materials or build quality per se, just that they designed around existing components to avoid the high initial cost of a bespoke SoC.