Because It's verbose and I don't like it?

It also means we have a static attribute to listen for so we don't need to listen to every attribute change making the attribute filter more performant.

I have personally never liked data-action. I find that the markup easily gets lost when refactoring, and it also presents a CSP issue when unsafe functions are bound to controller.

Further Reading: https://github.com/hotwired/stimulus/blob/main/SECURITY.md

I don't find myself reaching for these things.