Stealing a run

The Laws make provision for penalising a batsman who attempts to 'steal a run', by trying to run to the other end while the bowler is running up to bowl. Should this occur the umpire is instructed, firstly, to call and signal Dead ball, to return the batsmen to the ends whence they started, to award 5 Penalty runs to the fielding side and to report the incident. Presumably this form of unfair play was more commonplace in the early days of the game, when cricket was very much an upper-class sport played for money bets between sides or individuals. The occurrence is so rare these days that we know of no-one who has ever witnessed it! This begs the question - why is it still mentioned in the Laws? The answer can only be that, were it to be removed, its removal might be taken by some as a tacit admission that such behaviour, because no longer mentioned, was therefore now permitted, and some batsmen would then start doing it!