You need a lot of warmfuzzies in order to motivate yourself to donate.
You think encouraging cash benchmarking is really important, and giving GiveDirectly more money will help that.
You want to encourage charities to do more RCTs on their programs by rewarding the charity that does that most enthusiastically.
You care about increasing people’s happiness and don’t care about saving the lives of small children, and prefer a certainty of a somewhat good outcome to a small chance of a very good outcome.
You believe, in principle, that we should let people make their own decisions about their lives.
You want an intervention that definitely has at least a small positive effect.
You have just looked at GDLive and are no longer responsible for your actions.
A nice example of the second part, value dependence, is Ozy Brennan’s series reviewing GiveWell charities.