Because soon you should be able to apply to become one of the first people to live on the first mars colony.
http://mars-one.com/en/
From what I have read, the goal of Mars One is to send humans to mars, who will start a mars colony. The first launch is planned for 2023, and they will continue to send more people there in groups of 4 during the program. Anyone can apply to be an astronaut, but the people who get accepted will end up living there for the rest of their lives. The selection process part will be a reality TV show. People will be selected based on how well they interact with each other. This TV show is also a way for them to raise the funds for this project.
I am a bit skeptical if this thing will ever happen. Their business plan relies on investors throwing money at the project with little to no chance of getting a profit. I am not sure if the colony will be able to do anything that will cause them to make money either. The idea of becoming one of the first humans on mars is tempting, though.
Having children is discouraged, though. That is a huge deal breaker for me because if I am going to live the rest of my life somewhere, I would want to have some kids. Once applications open up I am going to apply for shits and giggles, but I have little intention of following through with it if they pick me.