Interesting! I hadn't considered that connotation of git.

To Euro-English speakers, 'git' is a rather coarse pejorative term for a person:

http://www.etymonline.com/index.php?term=git

It's fairly vulgar, of a similar coarseness to calling someone a 'stupid fucker' in US terms.

The in-joke being that Mr Torvalds chose the name specifically to cause offense.