Yes, I understand that part, but if you are on the ledge for a while, the game suddenly turns into you being forced to approach no matter what stocks or %. I'm not trying to claim I know more than you do here.
It's not about who knows more but rather how you choose to look at the game or what you view as "fair play" by your standards.
If you have the lead, what reasons would you stay on the ledge for?
1- Create an opening by forcing an approach, which you can capitalize on.
2- Plank, which is not exclusive to MK. GnW can do it just as good as MK can IMO. Others that can plank to an extent are ROB and Pit. Others can in specific MU's as well.
Planking shys away from any sort of interaction while staying safe, maintaining your lead, and also running the timer out. The soul purpose of planking is to run the timer out. Why should someone be awarded for avoiding contact for an extended period of time(8 min)? It destroys the purpose of the competition which is to take all of your opponent's stocks. Even with LGL in place I've seen matches go to time from the result of planking and the player still not go over the LGL. Plenty of times enough to know that LGL is not as big a factor as some try to make it out to be, especially if you keep track of your ledge count.
tl;dr
You are in no way forced to approach by staying on the ledge with a percent lead, even with a LGL in place. I have yet to see someone DQed for going over the LGL after a timeout, at least in all the high profile matches I've seen occur that have gone to timeout since the LGL has been implemented