Foot's objection against the categorical imperative

[Aweuifhawe]

Recently I have been studying various moral theories and from discussing them I don't think I've fully grasped Foot's complaint against the distinction between hypothetical en categorical imperatives.

Please correct me if you think I'm wrong or add if you think something is missing.

As I understand it the hypothetical imperative (HI) is applicable when someone wants to achieve a certain goal.
It describes a normative necessity for the reaching of this goal, if you want to achieve this goal then you must want this mean to the goal, do x if you want y. When an action is deemed 'good' for reaching a certain goal it is HI.

The categorical imperative (CI) describes a objective necessity. Something that has to be obeyed no matter what. These actions are intrinsically good, irrespective of the consequences, do x just because. It is commonly stated as: act as if you want the maxime to be a universal law.

If I now correctly understand Foot, she means to object that CI is actually a HI because it doesn't necessarily make us act how the CI would need us to.
Not doing something while it is good according to the CI doesn't mean that someone is irrational. The CI doesn't give us a reason to act according to Foot?

Is the problem here that Kant thinks that if someone doesn't follow the CI and only acts out of self interest that then he wouldn't promote things like justice?
Where Foot thinks that we don't really need this coercion of the CI to act 'good'?

If I haven't been able to bring my question across in an understandable way, my apologies, please ask if anything is unclear.

[Lawrence Crocker]

Would be helpful if you quoted the passage from Foot.