Jesus, wtf was wrong with it? It was in response to Mr.Reloaded writing a giant apology letter for MZ to 'apologize for being a Sanji fan.' So the response was saying anyone that apologizes for being a fan should shoot themselves, as in don't apologize for being a fan of something. Maybe the shoot themselves may be taken wrongly, but that kind of exaggeration/figure of speech has been normal for years on the internet until recent days.