My boyfriend's dad, who is not technical whatsoever, endorsed me for git. I'm pretty sure he just saw the word git and thought, "Hehe, she's a git!"
I think the problem too is that LinkedIn offers people the path of least resistance to endorse people. Occasionally I'll see a message at the top of my profile saying, "Endorse X for Y & Z" and a button to approve it. I'm sure more times than not, people just approve endorsements without giving it a second thought.