Go ahead and see Ender's Game--OSC won't profit. I find that weird. Why not go ahead and make the man whose motives you despise box office poison, if you're the boycotting type? It doesn't have to be this paycheque you impact--why not all of them from here on in?
Also--if everyone who was going to boycott the movie boycotts the book instead--how will that have more impact than the original plan? Were people going to skip the movie to cut his profits, but still buy the book?