You're absolutely right.

Read this: http://www.reddit.com/r/todayilearned/comments/1bp44q/til_ge....

Basically, Lucas did the funding on his second movie, which encouraged him to use clever marketing strategies (since the profit was all for him).

So he came up with this idea of selling his boring movie to nerds (even though it's entirely unrelated) and it worked! He simply spotted an under-exploited demographic, an age-old business strategy. He's comparable to Steve Jobs, who found the hipster design demographic, for fabulous marketing genius.