Buying late also has the advantage that if the game is a technical disaster at first, you can wait some months until most of the bugs have been fixed and then still buy it and enjoy it anyways. Then you don’t have to go through the frustrating experience of trying to play a game that crashes or locks your progress due to bugs every half an hour.
They were probably thinking that by openly opposing it before it collected enough signatures, they would have given it more publicity and hence made more people sign it.