Also, the lawmakers of the game have progressively made things more difficult for refs and linos by complicating what used to be simple laws, the most prime example being offside. The original rules were mainly about facts - ie is there less then 2 defenders between the player and the goal when the ball is played forward. Now the officials have to add in a whole lot of interpretation - is the player 'active', or was he when the ball was played?
I think people have rose-tinted views of how wonderful the offside rule used to be. It wasn't changed on a whim, it was changed because people who were in an offside position weren't always interferring with the game, yet goals would be disallowed, and this led to complaints. So the rule has evolved in an attempt to take this into consideration.