Are you saying we should let the poor die off? Sure natural selection could help create "better" human beings. I really do agree. However, I don't agree on your choice of selection pressure. The economic system as it stands also creates a lot of negatives. Pollution and generally screwing people over are some obvious examples. These do not make healthier smarter people. I hate seeing economics compared to evolution, and I'm not sure you understand either.
Agreed, I think most people at least consider leaving facebook frequently and with facebook going public investors will push these annoying but lucrative features (Although I almost like this one). If I remember correctly myspace declined steadily after going public itself.