Earlier quoted context omitted.
I could be missing some shady history, but off the top of my head how about Square? Edit: Dropbox, Craigslist, GitHub, PayPal, Instagram, Tesla, SpaceX, Twitter Anyone feel free to jump in if I'm ignoring any exploitation or shadiness. Bad examples: Spotify and Snapchat.
Craigslist: https://en.wikipedia.org/wiki/Craigslist_Inc._v._3Taps_Inc . Github: https://en.wikipedia.org/wiki/GitHub#Departure_of_Tom_Presto... Paypal: https://www.google.com/search?q=paypal+scandal&rlz=1C5CHFA_e... Twitter: https://www.google.com/search?q=twitter+harassment+problem&r... Square: http://www.businessinsider.com/wsj-square-coo-resigned-after... So your list has dwindled to just Dropbox and Instagram.
Github: The point I'm arguing against is the idea that startups have to use exploitative and legally questionably business practices to succeed. This Github thing sucks, but it doesn't really have anything to do with business practices, and obviously nobody is arguing that startup leaders have to to be sexist to succeed.
PayPal: That scandal looks like it's related to PayPal Credit, which they acquired a decade after PayPal was founded. Not an example of something startups have to do to succeed.
Twitter: This is somewhat debatable, but it's a reasonable point. Maybe Twitter wouldn't have succeeded if it tried to stamp out harassment early on.
Square: Similar to Github. This sucks, but it's not really relevant to the point I'm trying to make. It is possible and relatively common for a startup to find massive success without relying on exploitation and potentially illegal business practices.