Short Sighted

Why is it that people are so short sighted? I am amazed at how many people consistently try to squeeze out a bit more money from a job, a client, a friend. Does no one realize that they will get that money, but they WILL completely screw themselves out of the opportunity for more business from that contact in the future?

I am convinced that this is one of the final stages of the economy crapponizing and must indicate that things will turn up.