GitHub already has pages and wikis and is heavily invested in GFM and is killing it in the commercial market. Why would they want a non-Ruby reST product?
> You can make money and serve the open source community at the same time.
And Gittip might turn out to be a way to do that.
Maybe Eric wants to be a person, not an acquisition target.
The interesting thing about Gittip is that there's no strings attached for receivers. We've already got a company advertising itself on the Gittip givers leaderboard (https://workforpie.com/). But there's a decoupling of corporate interests from personal interests on Gittip that I think is worth continuing to explore. Even if Gittip were filled with corporate donors, their contributions would still be anonymous to the receivers. There's no strings attached. To me, that's new and interesting.
github is not open source - they have a closed source service that is available for free, with limitations. Unless you meant that they are building a business based on an open source piece of software, which is a little different from e.g. Sentry.
Don't get me wrong: I love GitHub. It's a fantastic product and an inspiration to me. Instead of paying $7/mo for private repos, I choose to give back by gittiping members of the organization: