Advanced three-fingered aliens

There are a lot of movies that show aliens having three fingers.  That doesn’t make any sense, aliens are supposed to be evolved millions of years beyond us.  What is so evolved about having only three fingers?  Just imagine a three-fingered alien trying to type on a keyboard; it can’t even cover the home row.

I understand why so many aliens want to destroy the Earth.  Aliens land here and see us playing saxophones and flutes; and they get jealous because they can’t play those instruments.  If you think guitar hero is difficult on hard mode for a five-fingered person, just imagine what is like for a three-fingered alien. 

Aliens also have trouble with sign language.  It’s hard to develop an effective sign language when you only have three fingers on each hand.  Aliens are lucky if they can make good baseball hand signals, let alone sign with their hands.  That’s why so many aliens are telepathic.  Millions of years ago aliens were signing to each other and thought screw it, signing with three fingers is about as effective as communicating to humans through crop circles.