Git started winning people over because mercurial was atrociously slow. The real nail in the coffin was GitHub which truly was revolutionary. Nothing else really played a part.
Mercurial slowness was never a problem for me, and these were the times before SSD! It probably was slower but I used it on some pretty large codebases (NetBeans) and it was fine.
BitBucket was much better for me than GitHub because it offered free private repositories with 5 users, which just happens to be enough for a small team/company/startup.
Sun Microsystems picked Mercurial for OpenJDK/NetBeans/etc, Mozilla was on Mercurial.
I'm still puzzled how Git won because in my bubble it was a tool with much worse commands and 'metaphors' compared to Mercurial.
I think it's a big loss for the industry that we are all (me included) on git.
What do you mean by "there"?
If you mean you've been working that long my first VCS experience was with MS SourceSafe and quickly moving to CVS. So...
The first I heard of Git (as best I recall) I definitely knew it was from Linus.
How much earlier was Github than Bitbucket?
Bitbucket supported both Git and Hg.