I thought about this at one point too. I hope I am not a target of some righteous indignation as a result of the following statements, as I am probably not concise enough or plain wrong.
My thought on this matter is to offer the option to have an intermediary input profile after white balance. As can be seen in this wiki post
there are at least 2 points where a profile is necessary in raw processing. There can always be more as a colour profile is just a shortcut to series of matrix transforms meant to adapt colours into another working environment, correct colour balance and distribution, or compress them into a colour gamut.