I think maybe he decided to end the book that way to explain that you can only do so much before your time is up. To not waste time to be quick on things. Like winston when he finally thought he had the chance to do something they caught him and Julia. They could have done something against big brother but they didnt have the chance. He could have done something small with a big impact. Like Rosa Parks, she fought for what she thought was right. She refused to sit in the back of the bus. She had the right to sit anywhere she wanted she paid like everybody else did. It wasnt the biggest thing ever but it helped against racial segregation and that action started the montgomery bus boycott . If she wouldnt of have refused to move i think that maybe it would of had taken longer for everyone to be treated equally or maybe it would of never happened.
http://www.achievement.org/autodoc/page/par0bio-1