Sledging is just a way of trying to get an advantage that is dressed up as part of the game but is essentially cheating. If someone was talking to the batsman during delivery it would be cheating, so the distracting abuse takes place outside of the delivery stride so what?
And it isn't banter, banter is where all parties involved are on the same page, taking it in the same spirit and noone objects to what is being said in a light-hearted way. Sledging should be banned outright, except from the winter olympics of course. They should let their cricket do the talking, to me sledging is one of those things the best sides perfect to make sure they stay at the top. Like every little advantage a team like man utd will strive for, by contesting every decision, surrounding the referee, making comments in the media about referees etc. They may or may not be the best team in the competition concerned, but they try and make sure their football is backed up with as many decisions as they can get. It is a form of cheating, they'll get decisions they shouldn't have and refs may not book their players when they should have - with carefully scheduled public comments in the media about how they are persecuted
DISCLAIMER : I am using the mancs as an example, could just as easily be any other team looking to make 50-50 into 51-49, 52-48 etc
So in cricket terms it is like players that don't walk, they may not consider themselves cheats but they are. They are forcing the umpire to give them out even if they know they are out, therein they would happily remain not out when they are indeed out. Laws don't say anything about having to be given out as far as I recall, they merely state modes of dismissal. The umpires are there to enforce the laws when necessary, they will make mistakes and batsmen prey on that. Hussain did that in Sri Lanka, straight off the bat to silly point, he was out but didn't walk and got TWO lives on his way to a crucial 100. He may not consider that cheating but I do, and it is. Even fielders are now hiding behind "not sure" a bit, if they know the ball has touched the ground in a 'fair catch' decision then they should say so, not leave it up to probably inconclusive replays to get them a catch. To me knowing you are out, or knowing the batsman is not out, but forcing the decision to replay or the umpire is cheating without any doubt in my mind. You are taking a clear cut verdict that you can give yourself and giving it to someone else who might make the wrong verdict, so you are increasing your odds of getting a verdict you want knowing that that verdict could be wrong - perhaps with the justification it wasn't you giving the wrong verdict even though you were the one forcing it.
But back to sledging, attempting to gain an advantage is cheating. Some might say it is fair, but is it? Do the people doing it ask if the recipient minds?!?! "Excuse me mister whose sister I slept with, do you mind if I say that?" If he replies "wasn't me sister, it was me grandpa but whatever" then fair enough, but just because aussies (and others) are hardened against that kind of abuse, doesn't justify abusing others. We're not all at the same level of mental strength, and I doubt those dishing it out consider the boundaries of acceptable and unacceptable, or indeed know what might really hit a nerve on a sensative issue. Best just to ban it outright, it doesn't enhance cricket it's probably more something that simpletons do to pass time.