>Investors were in this for a huge exit
I think these excerpts from your comment and also DHH's "VCs need their pound of flesh" are not helpful for readers on how to analyze the situation. They (maybe unintentionally) taint the discussion.
Github is an entity owned by human beings. The founders included Chris Wanstrath, Tom Preston-Werner, PJ Hyett, and Scott Chacon. Therefore, emphasizing that "investors wanted a big exit" is (inadvertently) omitting that those 4 founders may have also wanted a big exit as well. The DHH quote also misdirects people into thinking the VCs are the bad guys. Instead, we have to remember that the 4 founders have to sign off on the documents at closing to get the $350 million. They had to do presentations to convince investors to give them $350 million.
We have to include the founders' thinking about Github's future and not just outsource our frustration to those "evil VCs". VCs cannot give money to a startup if the founders don't want it. (E.g. Craig Newmark refuses VC money for craigslist.org.)