I honestly think the security/privacy arguments are the only valid argument against requiring JS as standard.

The idea of browsers sending data that the user has explicitly elected to send (in addition to, if we're being pedantic, that the server put there in the first place) is very compelling in this day and age - only problem being that in order for that to have any meaningful impact on web security in the general case, you'd have to more or less universally deprecate JS support, which would set the web in a very different direction indeed.