Why has political correctness gone out of control?

"Political correctness" plays an increasingly major role in society, not only to keep others from becoming offended, but also for accuracy. For instance, Native Americans are no longer called Indians because the term "Indian" could easily be confused with somebody who lives in or is from India. "Happy Holidays" is used to include every holiday during a given time so that there is no confusion as to which holiday a person could be talking about.