People's purpose in life, differs wildly, from person to person. There is a huge percentile of people who will probably never be able to afford to retire. Another decent size chunk, will not be able to do so till there "Official" retirement age, rapidly heading towards 70. 

Not having to work, early retirement, is a goal for many, me included, so the earlier I can do that, the better. I'd much rather be travelling the world and seeing the bits I've not already managed to. If I get bored, I might start a little business, who knows. It's all about having that freedom of choice.