There isn't necessarily a conflict between wanting to behave according to an arbitrary set of ethics, and being rational.

The ethics don't need to make sense universally any more than a particular variety of cheesecake needs to have universal appeal.

As an aside, the issue reminds me of Douglas Adams' cow who wants to be eaten: https://nhseb.org/case-library/the-cow-at-the-end-of-the-uni...