It's the adult way to punctuate. Seriously. Those who argue against the Oxford comma claim that they were taught in grade 2 that commas in a list mean "and," so if you already have an "and" before the last item in a list, you do not need a comma. For example, Grade 2: She came home with a book, a toy, a bat and a ball. Oxford: She came home with a book, a toy, a bat, and a ball. or She came home with a book, a toy, and a bat and ball.
How weird is that: such a common item of punctuation having such varied use in different languages? This is how we put a comma in a Russian language list. It seems weird to me that you would put a comma after the next-to-last item on the list. There's no particular logic behind it: we just don't have the Oxford comma in Russian.Grade 2: She came home with a book, a toy, a bat and a ball.
That line of argument doesn't make a whole lot of sense. If commas meant "and" then why not use semicolons instead? (I'm not trying to argue with you; I'm just putting into text something I noticed.)
It doesn't make a lot of sense, but that's how they teach children to punctuate a list. They give them this sentence, "He came home with a book and a toy and a bat and a ball." Then they tell the junior units to put a comma where the ands are -- except the last one. I don't think they get to semicolons till at least grade 8, if ever.