Well, although I haven`t given it a lot of thought, it could increase the speed and excitement of play. Given the fact that the level of athleticism and the skill of the players has increased a fair bit in the last few hundred years, it might be well worth a trial in a minor league.
Of course... the ends of such a change may be perceived simply as an attempt to increase viewership and therefore only about money.
One thing that does come to mind is this... would you want to play defense without the offside rule for 90 minutes on a hot dayÉ