The Categorical Imperative could be considered a foundational principle of morality. It is grounded in the belief that moral actions must be guided by rationality and universalizable principles, rather than emotions or consequences. I don’t really see what it wrong with that.
That sounds good, but there’s a lot wrong with it. We need emotions and consequences to govern us morally. Rationality can guide us up some weird paths. I think that with his Universal Categorical Imperative, Kant was tackling the “bindingness” problem: i.e., what makes a moral principle binding, why should I follow a moral principle. Kant said, because if everyone did what you are proposing to do (e.g., lying), the world wouldn’t work. However, this falls apart immediately because there are always valid exceptions.
This nuanced understanding of morality respects both individual dignity and the collective welfare of the group. I don’t see this as difficult to understand or why it should be elevated to some form of special knowledge.
You’re already a moral person, so you don’t need anything else than a reminder to behave well. Other people are seriously screwed up when it comes to morality, and require some basic education. It doesn’t have to be rocket science.
As for the questions, why bother, and what’s it all for? We bother for a number of reasons, partly because it’s a fiendishly difficult puzzle to understand, and also, knowledge of any kind is assumed to have a potential use at some time or other.
I think the task is to come up with alternatives to utilitarianism, consequentialism etc., which are an intuitive way in but don’t actually really go anywhere in the real world. A good alternative is morality as collaboration – both what happens within the collaboration, and its goal, are subjects for morality.