Why are rooks so awesome?

It really hurts to lose a rook.  That pair of rooks is so formiddible.  Is it because they pair up?   Because they cover more squares than other pieces?  

I don't know.    I guess the fact that you can checkmate with a king and a rook but not with a king and a knight or a king and a bishop or a king and a piece of cake, says it all.

Or does it?

I've also heard rooks aren't everything.  It's what's in your heart that counts.  Even a person who isn't very good rooking can be a true gem inside.

I'd say it's because they're the next best piece from the queen. (Bishops are all right, but limited). And if they're doubled up, most exchanges can't hold with a rook cannon. 2 pieces>rook. 

It's because of the crenels