Does hearing a commentator apologise for it mean the child didn't hear it? That's why I find it pointless, they're better off ignoring it than going out of their way to point out that it happened.
Gary Neville did it best during the United game, Chelsea fans singing "F*ck off Mourinho" after the little fracas at the end of the game very clearly and he commented "and now they're serenading him"
My bigger complaint with swearing on the TV at the moment is when you watch a UFC event (MMA) that goes on until the early hours of the morning with people punching, kicking and choking seven bells of sh*t out of eachother, blood everywhere and BT Sport will mute the post fight audio if one of the fighters says a naughty word...