Apologies by coverage I should've wrote discussion point. But look at the discussion it's created here alone, and I'm sure it's going on on Reddit and god forbid, the cesspool of Twitter.
But you've kind of proved the point by the fact that it's still even on the BBC sport page meriting an entire article along with the BBC leading with it on the sport section on Breakfast yesterday. How often does it happen that a chant like that get anywhere near the news?
You've mentioned about people's families being off limits which is fine, I'd cringe if fans were singing about a disabled child or family tragedy for example. Calling someone's mum a slag though is so small time and as I & others have described it, playground, especially when by all accounts she's had some 'internet moments' that people have clearly picked up on.
Going back to the Rat chant for Bruno or comparing Jonjo Shelvey to Voldemort, I can't understand how they are in any way better, in fact I'd argue it's worse because it's physical appearance rather than actions. All chants like that are designed to degrade the player from whichever angle people can get at them. So really, if we're going to get defensive about one, then we should be defensive about most of them.