Was this a one time thing?

If so: This seems like a classic case of "Just move on".
Seriously. We established that even in that situation the skill can be used for good and bad and there is no need to take away the good because some people are jerks (or might used it to early).
Its not game breaking in any way and while it can be annoying, it can also be used for good, so...

If its not a one time thing, I'd have to ask: Is this a new trend on your data center? Or are you running with this person on a regular basis? If so... why?

Limit breaks arent only used to kill the boss at 1% - most groups are using a LB in the middle of the fight in O7S. Or generally as soon as it hits 3 bars in Savage/EX-Primals in order to get a second LB (unless it needs to be saved for a certain mechanic).
And sometimes you can time that very badly - thouught that now was a safe moment to do it and... there are AoEs appearing at your feet!
Or you have a situation like in Chrysalis, where you want to use the LB on the aether-rift-thingie instead of on the boss. Cant tell you how many LBs Nabriales has eaten though, even after people were told not to use it on him...

Do you want to enable tank-lb alltogether btw? Because except for a few fights, it never has to be used, so if a tank uses it and wastes the 3 bars...

Seriously, in dungeons, 24-man raids and NM-primals this shouldnt make or break the run (most bosses are killed without the LB ever being touched, at least thats my experience).
So the only content where this could matter is Savage - which you should do with a trustworthy group in the first place.

Oh also: everyone except bard and maschnist has an ability to prevent Rescue alltogether - unless I'm terribly mistaken, your knockback-ability should also cancel out Rescue (I vaguely recall me trying that with Tempered Will and Rescue at the beginning of SB). So if its bothering you so much... pop Arms Length before you use your LB.