Another, selfish reason to donate to a broad variety of causes is to claim moral authority over people who don’t donate at all. Say you donate mainly to a “fringe” cause area, and some non-EA is hard on you for this. Then you can respond by saying “well I also donate small amounts to a variety of other causes too, including some you would agree with, to avoid getting attached to a particular cause; what are you doing?” At which point the person you’re talking to gets embarrassed if they don’t donate at all.
Another, selfish reason to donate to a broad variety of causes is to claim moral authority over people who don’t donate at all. Say you donate mainly to a “fringe” cause area, and some non-EA is hard on you for this. Then you can respond by saying “well I also donate small amounts to a variety of other causes too, including some you would agree with, to avoid getting attached to a particular cause; what are you doing?” At which point the person you’re talking to gets embarrassed if they don’t donate at all.