• Ludum Dare has never been about themes -- it's about making games and having fun. You can make a game and have fun without a theme, and if you really hate it, you can adapt or ignore it.
• The theme is there purely for inspiration, not for putting unnecessary restrictions or challenges on people. and I personally think there is a much better chance of developing new creative ideas when you're presentend with a theme you didn't expect or wish for.
• If you've been participating for several years and still annoyed about themes, you should either rethink your priorities or pick another one of those hundreds of game jams out there. The voting process is democratic, so by definition, the least annoying theme will be picked -- your opinion is no more valuable than everyone else's.

OK, I'm done complaining now. I wish you all a great jam this weekend! :)