default for quotRem in terms of divMod?

In class Integral, divMod has a default in terms of quotRem. (quot,rem,div,mod all have defaults as the both-function they're part of.) I'm sure divMod is more natural than quotRem to implement for some types... so why doesn't quotRem have a default in terms of divMod? it has no default! Then the "minimal to implement" will change from (toInteger and quotRem) to (toInteger and (quotRem or divMod)). Isaac