I actually think
@indiaholic is right in that the main problem is that it's barely used, and as such reeks as a kind of desperation when it is. West Indies using it in tight chases during the Under 19 World Cup really rubbed me the wrong way, because it's not like it was something they employed in other scenarios, and on at least
one occassion was employed when the batsman wasn't even really backing up too far but had rather just started backing up assuming the bowler was going to actually bowl the thing.
Losing your wicket because you think there's a run on a fielder's arm when there's only 0.92 of a run is also disproportionate but no-one other than maybe me wants to change the penalty for that.
If bowlers were confident in doing it whenever batsmen starting leaving a bit early I think it'd be accepted a lot more, and as a result batsmen would just stop backing up before they saw the ball released (which is fine IMO). But as it is now, it tends to manifest itself in tight situations when the stakes get higher more than anything else, and that sucks.