Nobody's perfect.
I can say that the ARC will never ever get another red cent from me. And my charitable contributions have doubled since then...
I haven't cut it to zero but, like you, I've shifted my charitable contributions from ARC to other organizations.
Forbes.com has a great listing on the efficiency of charitable organizations. Even after checking out their efficiency, one needs to check out their mission statements and programs. Lots of charities have politically oriented programs that conservatives and libertarians would find objectionable.