RBI's

I've had a couple of people, I guess staffers on the grammar police, correct me when I've said, "RBI's. As in, "Helton had three RBI's last night."
These morons will say, "It's not RBI's. It's not 'Runs Batted In's.' It's R'sBI."
Maybe RBI's isn't grammatically correct but the day I say "R'sBI is the day I stop following baseball.
Seriously, what kind of idiot really gets upset at RBI's? It's only been called RBI's since the beginning of time. Actually, since the beginning of baseball. I don't believe baseball was around when time began.
Perhaps this post is a step in the right direction in setting the R'sBI people straight. Or, maybe a better measure would be to punch the next person who corrects me after I say RBI's right in the nose. There's your bleeping R'sBI.
Had to get that off my chest.