If u want to get very analytical, you could say something about forcing the players to consider the consequences of their words.
If the correct word isn't guessed in time, the 'hangman' dies. This is directly linked to the player's (or players') inability to figure out the word, which in a real life situation would place the fault in their hands. In doing that, the game makes the players think carefully about what they say so they avoid killing the hangman.
hope this helps!