The nobel prize committee is far from "an arbitrary commmittee" as far as I know.
At least for the nobel prize in physics I know it's peers who decide and I'd assume it's the same for the other subjects, and it's not just "arbitrary people who have PhDs within the subject" either, it's a few selected ones who are well known in their fields.
At least for the nobel prize in physics I know it's peers who decide and I'd assume it's the same for the other subjects, and it's not just "arbitrary people who have PhDs within the subject" either, it's a few selected ones who are well known in their fields.