General Stock Cam Question

[learyw]

I'm going putting a new crate engine in my 78 K20 (part 809-12681429). Before I drop it in, I think I'm going to put in a mild Vodoo cam (part 10120701). This should give me a little performance bump.
This got me thinking. Why do stock motors come with such mild cams? What am I giving up by swapping out the factory cam? The engineers clearly designed that cam for a purpose? Why are they hesitant to put even a slightly more aggressive cam in stock motors? Fuel efficiency? Reliability? Cost? More generic so it fits multiple applications? There has to be a reason...Hoping someone had some insight. Thanks!