Don't know about the rest, but I switched from SVN to git before I even heard of Github for my personal project and also in the company I was CTO at the time.

Don't know about the rest, but I switched from SVN to git before I even heard of Github for my personal project and also in the company I was CTO at the time. Two things were decisive: being able to commit and browse the whole history while offline and the fact that my main dev machine was Linux so it worked faster than anything else.