Possibilities mentioned so far:
(1) Fame for attacker
(2) Excuse for other problems at GitHub
(3) Competitors
Not sure I find any of these is more convincing than the next or very convincing at all.
GitHub seems to be one of the least offensive businesses around but still gets attacked on a regularly. It's popularity might make it a target but don't those running botnets have better targets? And wouldn't they publicize their exploits?
And I can't believe GitHub would use it as an excuse. A DDoS attack has clear evidence that their entire devops team and many of their suppliers would have first hand knowledge of. If word leaked out it would be pretty embarrassing.
Lastly would a competitor risk destroying their entire business if found out. People are irrational and stupid but that would be crazy.
