The offside rule is silly, arbitrary, leads to the defense attempting to form lines in the back row to "catch" the offense offsides rather than simply playing D, is very difficult to call because it requires visualization of two places at once, and takes away from the game.
Better would be to get rid of the offsides rule entirely, or, if offsides is absolutely desired to avoid goal sitting, make it a hockey style line.
Having the offsides line depend on where the defenders are standing takes away from the game.
I recognize that stalwarts will defend it because "that's the way the game is played and I am a purist," but it detracts from the game.