Few universal principles exist in organizational behavior because

Human beings are difficult, and few, if any, simple and universal principles explain organizational behavior. Because we are not similar, our ability to make simple, accurate, and sweeping generalizations is inadequate. 

That doesn't mean, of course, that we can't propose a reasonably accurate explanations of human behavior or make valid predictions. It make sure that OB concepts must reflect situational, or possible conditions.

For instance: OB scholars would avoid stating that everyone likes complex and challenging work. Why?

Because not everyone wants a perplexing job. Some people prefer routine over diverse, or simple over complex. A job attractive to one person may not be to another; its appeal is contingent on the person who holds it.