Hussar
Legend
I can agree with that. Back to the 3d6 default. We know it was the default because the other methods listed were explicitly called alternative methods. That means that none of them, 4d6 drop the lowest included, could possibly have been the default. I don't know why Gygax would make the default worse than the primary alternative method, but he did.
An alternative interpretation is that 3d6 in order was a holdover from ODnD. It's mentioned in 1e for that fact and players are told that it doesn't work so here are four alternatives to something you shouldn't use.