There's a couple different reasons I ended up going with this solution for my site:

1) Most of the time, integrating social networks into your site means either a) using widgets that are hard to work into the main site flow or b) having a backend to pull and integrate social media posts for you. This solution essentially provides B without needing to maintain a backend.

2) When planning my site refactor, Github Pages appealed to me because of its speed and simplicity. This lets me preserve the site automation that would previously have required a CMS, and because the site is static and hosted by Github, I don't need to worry about bandwidth or usage limits.