They matter to people who aren't Utilitarians (like me!). I'm much more interested in motive than I am in outcome (although I like Good Things, just like everyone else).

Here's a hopefully intuitive framing: actions are built on outcomes, while institutions are built on motives. It's hard to imagine a consequential derivation of fundamental and inviolable human rights, for example: there will always be cases and circumstances where a consequential view of morality enables you to engage in casuistry to suit the occasion. I'd much rather build (and live under) practical moral systems where things stay right and wrong.

(To be clear: motive itself is not the moral object, in my view. Motive is merely the thing being questioned. The moral object is the moral law.)