my guess (like what i think soccer16 was trying to say) is that this rule requires one less thing for a ref to interpret (that's gotta be a good thing, right?)
i've seen many, many pages on this board dedicated to this discussion. just think about all the possibilities: it's okay if the player runs towards his own fans; unacceptable if he is facing the opposition; he is allowed to hug his teammates, but no one in the stands; the player is allowed a diving header, but only if it's raining and the field is slick; allowable if your team is either losing at the time, or winning by fewer than three goals; it's more okay if the celebrating player does not normally score for his team, less okay if he does; no vulgar language allowed, i.e., "heck yes" is allowable, "hell yes" is not; and on and on and on...
do you REALLY want to see either:
1) a rule written specific enough that anyone can easily decide whether the celebration is acceptable or not, OR
2) a rule written in such a way that a referee is given some amount of leeway, based on his/her best judgement?
personally, i prefer it the way it is now; and if it's an important enough goal, give the player the go-ahead to celebrate and just take the yellow.